The Collaborative International Dictionary of English v.0.48:

Substantive \Sub"stan*tive\, a. [L. substantivus: cf. F.
   substantif.]
   1. Betokening or expressing existence; as, the substantive
      verb, that is, the verb to be.
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   2. Depending on itself; independent.
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            He considered how sufficient and substantive this
            land was to maintain itself without any aid of the
            foreigner.                            --Bacon.
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   3. Enduring; solid; firm; substantial.
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            Strength and magnitude are qualities which impress
            the imagination in a powerful and substantive
            manner.                               --Hazlitt.
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   4. Pertaining to, or constituting, the essential part or
      principles; as, the law substantive.
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   Noun substantive (Gram.), a noun which designates an
      object, material or immaterial; a substantive.

   Substantive color, one which communicates its color without
      the aid of a mordant or base; -- opposed to adjective
      color.
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The Collaborative International Dictionary of English v.0.48:

Substantive \Sub"stan*tive\, n. [Cf. F. substantif.] (Gram.)
   A noun or name; the part of speech which designates something
   that exists, or some object of thought, either material or
   immaterial; as, the words man, horse, city, goodness,
   excellence, are substantives.
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The Collaborative International Dictionary of English v.0.48:

Substantive \Sub"stan*tive\, v. t.
   To substantivize. [R.] --Cudworth.
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WordNet (r) 3.0 (2006):

substantive
    adj 1: having a firm basis in reality and being therefore
           important, meaningful, or considerable; "substantial
           equivalents" [syn: substantial, substantive]
    2: defining rights and duties as opposed to giving the rules by
       which rights and duties are established; "substantive law"
       [syn: substantive, essential] [ant: adjective,
       procedural]
    3: being on topic and prompting thought; "a meaty discussion"
       [syn: meaty, substantive]
    n 1: any word or group of words functioning as a noun