(idiomatic, derogatory) Thinking or acting as if one is superior, as by pretending to be of a higher class or having greater authority than is the case.

(intransitive, transitive) To open. / (intransitive) To reveal oneself; to share personal information about oneself; to become communicative. / (intransitive) To commence firing weapons.

(idiomatic) To "be a man about it"; to do the things a man is traditionally expected to do, such as taking responsibility for the consequences of one's actions; displaying bravery or toughness in the face of danger, adversity, or a challenge; providing for one's family, etc. (Compare man (“brace oneself, steel oneself”).)

(baseball) Used by an umpire to invite the next batter to the batter's box, especially at the beginning of a half-inning.

simple past tense and past participle of stand up

(transitive) To speak or act in support or defense of (a person, a cause, a belief, or the like).

(transitive) To seal with a wall.

(transitive) To object to or interfere with the actions of (someone seen as bullying, pushy, or controlling). / (transitive) To withstand, to weather, to survive in spite of.

Alternative spelling of upbeat

simple past tense and past participle of use up