get off one’s rear

get off (one's) rear

slang To start doing something, especially after a period of unproductivity or laziness. Grandma will be here in 30 minutes, so get off your rear and move this junk out of the living room! Ted needs to get off his rear for a change and make an effort around here.
See also: get, off, rear
Farlex Dictionary of Idioms.

get off one’s rear

in. to get up and get busy. (Euphemistic for Get off my ass!) It’s time to get off your rear and get to work.
See also: get, off, rear
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • get off (one's) rear
  • get off (one's) butt
  • wuss out
  • wuss out (of something)
  • give (something) a lick and a promise
  • wimp out
  • wimp out of something