agent noun /ˌeɪ̯.d͡ʒənt ˈnaʊ̯n/ noun1 •A noun that denotes an agent (human or nonhuman) that performs the action denoted by the verb from which the noun is derived.The agent noun “cutter” means a person who cuts, or a thing that is made to or is able to cut something. formsagent nouns