To act hastily
hasten, be quick, make haste, bestir oneself, bustle, rush, make short work of, scoot, work at high speed, dash on, hurry about, bundle on, run off, sally, work under pressure, hurry up, lose no time, make time, speed, act on a moment's notice, turn on the steam*, step on the gas*, get cracking*, don't spare the horses*, step on it*, fly about*, put on a burst of speed*, dig out*, dart to and fro*, race one's motor*, floor it*, shake a leg*.
Antonyms delay*, lose time, procrastinate.