The Collaborative International Dictionary of English v.0.48:

Garnishment \Gar"nish*ment\, n. [Cf. OF. garnissement
   protection, guarantee, warning.]
   1. Ornament; embellishment; decoration. --Sir H. Wotton.
      [1913 Webster]

   2. (Law)
      (a) Warning, or legal notice, to one to appear and give
          information to the court on any matter.
      (b) Warning to a person in whose hands the effects of
          another are attached, not to pay the money or deliver
          the goods to the defendant, but to appear in court and
          give information as garnishee.
          [1913 Webster]

   3. A fee. See Garnish, n., 4.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Trustee \Trus*tee"\, n. (Law)
   A person to whom property is legally committed in trust, to
   be applied either for the benefit of specified individuals,
   or for public uses; one who is intrusted with property for
   the benefit of another; also, a person in whose hands the
   effects of another are attached in a trustee process.
   [1913 Webster]

   Trustee process (Law), a process by which a creditor may
      attach his debtor's goods, effects, and credits, in the
      hands of a third person; -- called, in some States, the
      process of foreign attachment, garnishment, or
      factorizing process. [U. S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

garnishment
    n 1: a court order to an employer to withhold all or part of an
         employee's wages and to send the money to the court or to
         the person who won a lawsuit against the employee

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "garnishment":
   adjunct, adornment, angary, annexation, annexure, arrangement,
   attachment, certiorari, citation, collectivization, color,
   color patterns, commandeering, communalization, communization,
   confiscation, decor, decoration, distraint, distress, elaboration,
   embellishment, emblazonment, emblazonry, embroidery,
   eminent domain, execution, expropriation, flourish,
   flower arrangement, furniture arrangement, garnish, garniture,
   habeas corpus, illumination, impoundment, impressment, levy,
   monition, nationalization, ornament, ornamentation,
   right of angary, sequestration, socialization, subpoena, summons,
   trim, trimming, venire, venire de novo, venire facias,
   window dressing, writ of summons



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

GARNISHMENT. A warning to any one for his appearance, in a cause in which he
is not a party, for the information of the court, and explaining a cause.
For example, in the practice of Pennsylvania, when an attachment issues
against a debtor, in order to secure to the plaintiff a claim due by a,
third person to such debtor, notice is given to such third person, which
notice is a garnishment, and he is called the garnishee.
     2. In detinue, the defendant cannot have a sci. fac. to garnish a third
person unless he confess the possession of the chattel or thing demanded.
Bro. Abr. Garnishment, 1, 5. And when the garnishee comes in, he cannot vary
or depart from the allegation of the defendant in his prayer of garnishment.
The plaintiff does not declare de novo against the garnishee; but the
garnishee, if he appears in due time, may have oyer of the original
declaration to which he pleads. See Bro. Abr. Garnishee and Garnishment, pl.
8, and this title, passim.