get (one's) arse in(to) gear

rude slang To start being active or prepare to do something, particularly when one is inactive. Primarily heard in UK. A: "I told you I would take out the rubbish, didn't I?" B: "Well then get your arse into gear and do it already!" I really need to get my arse in gear and finish writing this paper—it's due tomorrow! Would you get your arse into gear already? The boss is expecting an update on this in an hour!

get your arse in gear

BRITISH, INFORMAL, VERY RUDE or

get your ass in gear

AMERICAN, INFORMAL, VERY RUDE

If you get your arse in gear, you make yourself start to do something, especially work. Note: The image in the following idioms is of driving a car. Of course Pat will be joining the project, if he ever gets his arse in gear. Note: You can also say that you get your arse into gear or get your ass into gear. You've got to get your arse into gear, girl. Nobody else is going to help you.

get your arse into gear

begin to move or take action, especially belatedly; hurry.