To say that somebody is not to do anything without receiving further instructions. / To say that somebody is obliged to do something without question.

(sports) on your mark, get set, go

(idiomatic) To have a miserable experience.

(literally, derogatory) To leave an Indian reservation to which one was restricted. / (US, politics) To break with one's party or group, usually temporarily.

To make a great effort.

(idiomatic) To make a major effort; to be very careful when doing something, especially to an extreme or excessive degree.

(idiomatic) To accompany someone in a passive manner, or to take a relatively passive or detached role in a project or group activity.

(Britain, colloquial) To launch into an animated diatribe, or passionate description or explanation of something.

(Britain, informal) An ordinary member of the public who intervenes, often at personal risk, to stop a troublemaker, hooligan or ne'er-do-well in the act of committing a crime.

(US) hide and seek