The cardinal number occurring after twenty and before twenty-two, represented in Roman numerals as XXI and in Arabic numerals as 21.

(card games) Blackjack. / (sports) A basketball-based game in which players attempt to score exactly twenty-one points.

(idiomatic) To succeed in a deception. / (idiomatic, with on) To fool, trick, or deceive.

Someone who hangs on, or sticks to, a person, place, or service. / (mining, historical) An onsetter.

(idiomatic) To speak lacking expertise, authority, or knowledge; to invent or fabricate facts. / (idiomatic) To assert something as true or valid; to bluff.

To don (clothing, equipment, or the like). / To fool, kid, deceive. / To assume, adopt or affect; to behave in a particular way as a pretense. / To play (a recording).

To grasp or grip firmly. / (idiomatic) To keep; to store something for someone. / (idiomatic) Wait a short while. / (idiomatic) To remain loyal. / (idiomatic) To persist.

(idiomatic) Delayed; postponed; suspended. / Waiting on a telephone call. / On reserve; being held for someone. / Pertaining to a telephone hold state.

(idiomatic, chiefly imperative) To wait a moment. / To hold, grasp, or grip. / (idiomatic) To keep; to store something for someone.

(frequency) One and only one time. / (temporal location) Formerly; during some period in the past. / (obsolete) At any time; ever. / (obsolete) One day, someday.