substantive

Short definition from Wiktionary

Adjective

1. 1
   Of the essence or essential element of a thing.
2. 2
   Of the essence or essential element of a thing: Constituting the substance of content rather than its style, and thus always nontrivial.
3. 3
   Having substance; enduring; solid; firm; substantial.
4. 4
   Applying to essential legal principles and rules of right.
5. 5
   Not needing the use of a mordant to be made fast to that which is being dyed.
6. 6
   Depending on itself; independent.
7. 7
   Of or pertaining to a substantive.
8. 8
   Actually and legally held, as distinct from an acting, temporary or honorary rank or appointment.

Noun

1. 1
   Ellipsis of noun substantive or substantive noun, a noun or a group of words (a noun phrase) that act as a noun (in a sentence).
2. 2
   Part of a text that carries the meaning, such as words and their ordering.

Verb

1. 1
   To make a word belonging to another part of speech into a substantive (that is, a noun) or use it as a noun.