The Collaborative International Dictionary of English v.0.48:

Attachment \At*tach"ment\, n. [F. attachment.]
   1. The act attaching, or state of being attached; close
      adherence or affection; fidelity; regard; an? passion of
      affection that binds a person; as, an attachment to a
      friend, or to a party.
      [1913 Webster]

   2. That by which one thing is attached to another;
      connection; as, to cut the attachments of a muscle.
      [1913 Webster]

            The human mind . . . has exhausted its forces in the
            endeavor to rend the supernatural from its
            attachment to this history.           --I. Taylor.
      [1913 Webster]

   3. Something attached; some adjunct attached to an
      instrument, machine, or other object; as, a sewing machine
      attachment (i. e., a device attached to a sewing machine
      to enable it to do special work, as tucking, etc.).
      [1913 Webster]

   4. (Giv. Law)
      (a) A seizure or taking into custody by virtue of a legal
          process.
      (b) The writ or percept commanding such seizure or taking.
          [1913 Webster]

   Note: The term is applied to a seizure or taking either of
         persons or property. In the serving of process in a
         civil suit, it is most generally applied to the taking
         of property, whether at common law, as a species of
         distress, to compel defendant's appearance, or under
         local statutes, to satisfy the judgment the plaintiff
         may recover in the action. The terms attachment and
         arrest are both applied to the taking or apprehension
         of a defendant to compel an appearance in a civil
         action. Attachments are issued at common law and in
         chancery, against persons for contempt of court. In
         England, attachment is employed in some cases where
         capias is with us, as against a witness who fails to
         appear on summons. In some of the New England States a
         writ of attachment is a species of mesne process upon
         which the property of a defendant may be seized at the
         commencement of a suit and before summons to him, and
         may be held to satisfy the judgment the plaintiff may
         recover. In other States this writ can issue only
         against absconding debtors and those who conceal
         themselves. See Foreign, Garnishment, Trustee
         process. --Bouvier. --Burrill. --Blackstone.
         [1913 Webster]

   Syn: Attachment, Affection.

   Usage: The leading idea of affection is that of warmth and
          tenderness; the leading idea of attachment is that of
          being bound to some object by strong and lasting ties.
          There is more of sentiment (and sometimes of romance)
          in affection, and more of principle in preserving
          attachment. We speak of the ardor of the one, and the
          fidelity of the other. There is another distinction in
          the use and application of these words. The term
          attachment is applied to a wider range of objects than
          affection. A man may have a strong attachment to his
          country, to his profession, to his principles, and
          even to favorite places; in respect to none of these
          could we use the word affection.
          [1913 Webster]

WordNet (r) 3.0 (2006):

attachment
    n 1: a feeling of affection for a person or an institution [syn:
         attachment, fond regard]
    2: a supplementary part or accessory
    3: a writ authorizing the seizure of property that may be needed
       for the payment of a judgment in a judicial proceeding
    4: a connection that fastens things together [syn: attachment,
       bond]
    5: faithful support for a cause or political party or religion;
       "attachment to a formal agenda"; "adherence to a fat-free
       diet"; "the adhesion of Seville was decisive" [syn:
       attachment, adherence, adhesion]
    6: the act of attaching or affixing something [syn:
       attachment, affixation]
    7: the act of fastening things together [syn: fastening,
       attachment]

Moby Thesaurus II by Grady Ward, 1.0:

202 Moby Thesaurus words for "attachment":
   Amor, Christian love, Eros, Platonic love, accession, accessory,
   accompaniment, accounting for, addenda, addendum, additament,
   addition, additive, additory, additum, adherence, adhesion,
   adhesive, adjunct, adjunction, adjuvant, admiration, adoration,
   affection, affinity, affixation, affixing, agape, agglutination,
   allegiance, angary, annex, annexation, annexure, answerability,
   appanage, appendage, appendant, appliance, application,
   appurtenance, appurtenant, ardency, ardor, arrogation, ascription,
   assignation, assignment, attaching, attribution, augment,
   augmentation, binding, blame, bodily love, bona fides, bond,
   bonne foi, brotherly love, caritas, charge, charity, clasping,
   coda, collectivization, commandeering, communalization,
   communization, complement, concomitant, confiscation,
   conjugal love, connection, connection with, constancy,
   continuation, corollary, credit, decoration, derivation from,
   desire, device, devotedness, devotion, distraint, distress,
   eminent domain, etiology, execution, expropriation, extension,
   extra, extrapolation, faith, faithful love, faithfulness, fancy,
   fastener, fastening, fealty, fervor, fidelity, firmness, fixing,
   fixture, flame, fondness, free love, free-lovism, friendliness,
   friendship, gadget, garnishment, girding, good faith, heart,
   hero worship, homage, honor, hooking, idolatry, idolism,
   idolization, impoundment, impressment, imputation, increase,
   increment, joining, junction, juxtaposition, knot, lasciviousness,
   lashing, levy, libido, ligation, like, liking, link, linking, love,
   lovemaking, loyalty, married love, nationalization, offshoot,
   ornament, palaetiology, part, partiality, passion, pendant,
   physical love, piety, placement, popular regard, popularity,
   prefixation, reference to, regard, reinforcement, responsibility,
   right of angary, saddling, sentiment, sequestration, sex,
   sexual love, shine, side effect, side issue, socialization,
   spiritual love, splice, staunchness, steadfastness, sticking,
   suffixation, superaddition, superfetation, superjunction,
   superposition, supplement, supplementation, tailpiece,
   tender feeling, tender passion, tenderness, tie, tieing, troth,
   true blue, truelove, trueness, undergirding, uniting, uxoriousness,
   weakness, worship, yearning, zipping



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ATTACHMENT, crim. law, practice. A writ requiring a sheriff to apprehend a
particular person, who has been guilty of. a contempt of court, and to bring
the offender before the court. Tidd's Pr. Index, h.t.;  Grab. Pr. 555.
     2. It may be awarded by the court upon a bare suggestion, though
generally an oath stating what contempt has been committed is required, or
on their own knowledge without indictment or information. An attachment may
be issued against officers of the court for disobedience or contempt of
their rules and orders, for disobedience of their process, and for
disturbing them in their lawful proceedings. Bac. Ab. h.t. A. in the nature
of a civil execution, and it was therefore held it could not be executed on
Sunday; 1 T. R. 266; Cowper, 394; Willes, R. 292, note (b); yet, in. one
case, it was decided, that it was so far criminal, that it could not be
granted in England on the affirmation of a Quaker. Stra. 441. See 5 Halst.
63; 1 Cowen, 121, note; Bac. Ab. h.t.



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ATTACHMENT, remedies. A writ issued by a court of competent jurisdiction,
commanding the sheriff or other proper officer to seize any property;
credit, or right, belonging to the defendant, in whatever hands the same may
be found, to satisfy the demand which the plaintiff has against him.
     2. This writ always issues before judgment, and is intended to compel
an appearance in this respect it differs from an execution. In some of the
states this process can be issued only against absconding debtors, or those
who conceal themselves; in others it is issued in the first instance, so
that the property attached may respond to the exigency of the writ, and
satisfy the judgment.
     3. There are two kinds of attachment in Pennsylvania, the foreign
attachment, and the domestic attachment. l. The foreign attachment is a mode
of proceeding by a creditor against the property of his debtor, when the
debtor is out of the jurisdiction of the state, and is not an inhabitant of
the same. The object of this process is in the first instance to compel an
appearance by the debtor, although his property may even eventually be made
liable to the amount of the plaintiff Is claim. It will be proper to
consider, 1. by whom it be issued; 2. against what property 3. mode of
proceeding. 1. The plaintiff must be a creditor of the defendant; the claim
of the plaintiff need not, however, be technically a debt, but it may be
such on which an action of assumpsit would lie but an attachment will not
lie for a demand which arises ex delicto; or when special bail would not be
regularly required. Serg. on Att. 51. 2. The writ of attachment may be
issued against the real and personal estate of any person not residing
within the commonwealth, and not being within the county in which such writ
may issue, at the time. of the issuing thereof. And proceedings may be had
against persons convicted of crime, and sentenced to imprisonment. 3. The
writ of attachment is in general terms, not specifying in the body of it the
name of the garnishee, or the property to be attached, but commanding the
officer to attach the defendant, by all and singular his goods and chattels,
in whose hands or possession soever the same may be found in his bailiwick,
so that he be and appear before the court at a certain time to answer, &c.
The foreign attachment is issued solely for the benefit of the plaintiff.
     4.-2. The domestic attachment is issued by the court of common pleas
of the county in which any debtor, being an inhabitant of the commonwealth,
may reside; if such debtor shall have absconded from the place of his usual
abode within the same, or shall have remained absent from the commonwealth,
or shall have confined himself to his own house, or concealed himself
elsewhere, with a design, in either case, to defraud his creditors. It is
issued on an oath or affirmation, previously made by a creditor of such
person, or by some one on his behalf, of the truth of his debt, and of the
facts upon which the attachment may be founded. Any other creditor of such
person, upon affidavit of his debt as aforesaid, may suggest his name upon
the record, and thereupon such creditor may proceed to prosecute his said
writ, if the person suing the same shall refuse or neglect to proceed
thereon, or if he fail to establish his right to prosecute the same, as a
creditor of the defendant. The property attached is vested in trustees to be
appointed by the court, who are, after  giving six months public notice of
their appointment, to distribute the assets attached among the creditors
under certain regulations prescribed by the act of assembly. Perishable
goods way be sold under an order of the court, both under a foreign and
domestic attachment. Vide Serg. on Attachments Whart. Dig. title Attachment.
     5. By the code of practice of Louisiana, an attachment in the hands of
third person is declared to be a mandate which a creditor obtains from a
competent officer, commanding the seizure of any property, credit or right,
belonging to his debtor, in whatever hands they may be found, to satisfy the
demand which he intends to bring against him. A creditor may obtain such
attachment of the property of his debtor, in the following cases. 1. When
such debtor is about permanently leaving the state, without there being a
possibility, in the ordinary course of judicial proceedings, of obtaining or
executing judgment against him previous to, his departure; or when such
debtor has already left the state never again to return. 2. When such debtor
resides out of the state. 3. When he conceals himself to avoid being cited
or forced to answer to the suit intended to be brought against him. Articles
239, 240.
     6. By the local laws of some of the New England states, and
particularly of the states of Massachusetts, New Hampshire and Maine,
personal property and real estate may be attached upon mesne process to
respond the exigency of the writ, and satisfy the judgment. In such cases it
is the common practice for the officer to bail the goods attached, to some
person, who is usually a friend of the debtor, upon an express or implied
agreement on his part, to have them forthcoming on demand, or in time to
respond the judgment, when the execution thereon shall be issued. Story on
Bailm. Sec. 124. As to the rights and duties of the officer or bailor in
such cases, and as to the rights and duties of the bailee, who is commonly
called the receiptor, see 2 Mass. 514; 9 Mass. 112 11 Mass. 211; 6 Johns. R.
195 9 Mass. 104, 265; 10 Mass. 125 15 Mass. 310; 1 Pick. R. 232, 389. See
Metc. & Perk. Dig. tit. Absent and Absconding Debtors.