noun a person who listens to something being said or who hears something
noun the faculty of perceiving sounds
adjective related to the sense of hearing
noun A noun is a word that represents a person, place, thing, or idea. In this case, 'acou-' does not function as a noun.
noun the measurement of the acuteness or sharpness of hearing
noun a combining form meaning hearing, used in the formation of compound words relating to the sense of hearing