get one’s ass in gear
get (one's) ass in gear
rude slang To start being active or prepare to do something, particularly when one is inactive. I know you said you would take out the trash, but get your ass in gear and do it already! I really need to get my ass in gear and finish writing this paper—it's due tomorrow!
get one’s ass in gearand get one’s tail in gear
exclam. to get moving; to get organized and get started. (Usually objectionable.) Come on, you guys. Get moving. Get your ass in gear! Get moving, guys. Get your tail in gear and keep moving!