be·hav·ior·ist I. \-yərə̇st\noun (-s) : one who accepts or assumes the point of view of behaviorism II. adjective orbe·hav·ior·is·tic\ ̷ ̷| ̷ ̷ ̷ ̷|ristik, -ēk\ : of or belonging to behaviorism < behaviorist psychology > • be·hav·ior·is·ti·cal·ly\-tə̇k(ə)lē, -ēk-, -li\adverb