substantive

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Substantial; considerable.
• adjective Independent in existence or function; not subordinate.
• adjective Not imaginary; actual; real.
• adjective Of or relating to the essence or substance; essential.
• adjective Having a solid basis; firm.
• adjective Grammar Expressing or designating existence; for example, the verb to be.
• adjective Grammar Designating a noun or noun equivalent.
• noun A word or group of words functioning as a noun.

from The Century Dictionary.

• To convert into or use as a substantive.
• Betokening or expressing existence: as, the substantive verb.
• Depending on itself; independent; self-dependent; hence, individual.
• Substantial; solid; enduring; firm; permanent; real.
• Independent; not to be inferred from something else, but itself explicitly and formally expressed.
• In grammar, of the nature of a noun, usable as subject or object of a verb and in other noun constructions: as, a substantive word; a substantive pronoun; a substantive clause.
• noun In grammar, a noun; a part of speech that can be used as subject or as object of a verb, be governed by a preposition, or the like.
• noun An independent thing or person.
• In biology, concerning or pertaining to the construction or constitution of the parts of the bodies of organisms, as contrasted with the symmetry or merism of these parts in relation to one another.
• Milit., actual or real, as rank; having the actual rank of.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Gram.) A noun or name; the part of speech which designates something that exists, or some object of thought, either material or immaterial.
• adjective Betokening or expressing existence.
• adjective Depending on itself; independent.
• adjective Enduring; solid; firm; substantial.
• adjective Pertaining to, or constituting, the essential part or principles.
• adjective (Gram.) a noun which designates an object, material or immaterial; a substantive.
• adjective one which communicates its color without the aid of a mordant or base; -- opposed to adjective color.
• transitive verb rare To substantivize.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of the essence or essential element of a thing; as, "substantive information".
• adjective Having substance and prompting thought.
• adjective law Applying to essential legal principles and rules of right; as, "substantive law".
• adjective chemistry Of a dye that does not need the use of a mordant to be made fast to that which is being dyed.
• noun grammar A word that names or refers to a person, place, thing, or idea. Nouns and personal pronouns are always substantives by nature.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective defining rights and duties as opposed to giving the rules by which rights and duties are established
• noun any word or group of words functioning as a noun
• adjective being on topic and prompting thought
• adjective having a firm basis in reality and being therefore important, meaningful, or considerable