The Collaborative International Dictionary of English v.0.48:

specification \spec`i*fi*ca"tion\
   (sp[e^]s`[i^]*f[i^]*k[=a]"sh[u^]n), n. [Cf. F.
   sp['e]cification, LL. specificatio.]
   1. The act of specifying or determining by a mark or limit;
      notation of limits.
      [1913 Webster]

            This specification or limitation of the question
            hinders the disputers from wandering away from the
            precise point of inquiry.             --I. Watts.
      [1913 Webster]

   2. The designation of particulars; particular mention; as,
      the specification of a charge against an officer.
      [1913 Webster]

   3. A written statement containing a minute description or
      enumeration of particulars, as of charges against a public
      officer, the terms of a contract, the description of an
      invention, as in a patent; also, a single article, item,
      or particular, an allegation of a specific act, as in a
      charge of official misconduct.
      [1913 Webster]

   4. A detailed listing or description of the required
      properties of some object proposed to be built or bought;
      -- usually used in the plural; as, the building
      specifications require that it withstand an earthquake of
      magnitude 8; the program specifications require an option
      to change the menus.
      [PJC]

WordNet (r) 3.0 (2006):

specification
    n 1: a detailed description of design criteria for a piece of
         work [syn: specification, spec]
    2: naming explicitly
    3: (patent law) a document drawn up by the applicant for a
       patent of invention that provides an explicit and detailed
       description of the nature and use of an invention
    4: a restriction that is insisted upon as a condition for an
       agreement [syn: stipulation, specification]

Moby Thesaurus II by Grady Ward, 1.0:

136 Moby Thesaurus words for "specification":
   allocation, allowance, analysis, anatomization, assignment,
   atomization, attribution, boundary condition, bounding, cameo,
   catalog, cataloging, catch, cession, character, character sketch,
   characterization, circling-in, circumscribing, circumscription,
   circumstantiation, clause, concession, condition, consideration,
   definition, delimitation, delineation, demarcation, denomination,
   denotation, depiction, describing, description, designation,
   detail, details, determination, differentiation, disclosure,
   donnee, encincture, enumeration, escalator clause, escape clause,
   escape hatch, evocation, exception, exemption, expression,
   extenuating circumstances, fine print, fingering, fixing, given,
   grain of salt, grant, graphic account, grounds, hedge, hedging,
   hint, identification, identifying, image, imagery, impression,
   inclusion-exclusion, indication, indicativeness, inventory,
   itemization, itemizing, joker, kicker, limitation,
   limiting condition, limning, list, listing, manifestation, meaning,
   mental reservation, modification, naming, obligation, parameter,
   particularization, photograph, picking out, picture, pinning down,
   pointing, pointing out, pointing to, portrait, portraiture,
   portrayal, precision, prerequisite, profile, provision, provisions,
   proviso, qualification, rendering, rendition, representation,
   requirement, requisite, reservation, restriction, salvo,
   saving clause, selection, show, showing, signification,
   sine qua non, sketch, small print, special case, special treatment,
   specialness, specifying, stipulation, string, suggestion,
   symptomaticness, terms, ultimatum, vignette, vivid description,
   waiver, whereas, word painting



The Free On-line Dictionary of Computing (30 December 2018):

specification
spec

    (spec) A document describing how some system should
   work.

   (2001-02-06)


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

SPECIFICATION, civil law. A term used in the civil law, by which is meant a
person's making a new species or subject from materials belonging to
another. Bouv. Inst. Theolo. ps. 1, c. 1, art. 1, Sec. 4, Is. 4, p. 74.
     2. When the new species can be again reduced to the matter of which it
was made, the law considers the former mass as still existing, and,
therefore, the new species as an accessory to the former subject; but where
the thing made cannot be so reduced, as in the case of wine, which cannot be
again turned into grapes, there is no place for the fictio juris; and,
there, the workmanship draws after it the property of the material. Inst. 2,
1, 25 Dig. 41, 1, 7, 7. See Accession; Confusion; Mixtion; and Aso & Man.
Inst. B. 2, t. 2, c. 8.



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

SPECIFICATION, practice, contracts. A particular and detailed account of a
thing: example, in order to obtain a patent for an invention, it is
necessary to file a specification or an instrument of writing, which must
lay open and disclose to the public every part of the process by which the
invention can be made useful if the specification does not contain the whole
truth relative to the discovery, or contains more than is requisite to
produce the desired effect, and the concealment or addition was made for the
purpose of deception, the patent would be void; for if the specification
were insufficient on account of its want of clearness, exactitude or good
faith, it would be a fraud on society that the patentee should obtain a
monopoly without giving up his invention. 2 Kent, Com. 300; 1 Bell's Com.
part 2, c. 3, s. 1, p. 112; Perpigna on Pat. 67; Renouard, Des Brevets
d'Inv. 252.
     2. In charges against persons accused of military offences, they must
be particularly described and clearly expressed; this is called the
specification. Tytl. on Courts Mart. 109.