Pertaining to how a word modifies a verb, an adjective, or another adverb: The adverbial term in this sentence is "very": This is a very beautiful dress." The adverb "very" intensifies the adjective "beautiful".

An adverb that modifies a verb answers any of four questions: "Where?", "When?", "In what manner?", and "To what extent?"

An adverb that modifies an adjective or another adverb, answers "To what extent?" When an adverb functions in this second manner, it is often called an "intensifier" because it increases or decreases the intensity of the adjective or the adverb it modifies.