any member of a class of words that are formally distinguished in many languages, as in English by taking the past ending in -ed, that function as the main elements of predicates, that typically express action, state, or a relation between two things, and that (when inflected) may be inflected for tense, aspect, voice, mood, and to show agreement with their subject or object.

adjective

auxiliary , denominative , indicative , intransitive , irregular , modal , periphrastic , phrasal , prepositional , subjunctive , substantive , suppletive , transitive

noun

deponent , gerund , infinitive , participle , verbification

verb

verbify