n. The act, manner, or amount of using; use: the usage of a technical term; an instrument that measures water usage. n. The act or manner of treating; treatment: subjected the car to rough usage. n. A usual, habitual, or accepted practice. See Synonyms at habit.n. The way in which words or phrases are actually used, spoken, or written in a speech community.n. A particular expression in speech or writing: a nonce usage.