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.n. 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.n. An independent thing or person.To convert into or use as a substantive.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.