Get (one's) arse in gear British slang rude
You can use this slang under the alternative forms: "get (one's) arss into gear", "put (one's) arse in gear", "have (one's) arse in gear".
Used to ask somebody to do something quickly in an impolite manner
You promised faithfully to cook dinner for me, then get your arse in gear and do it!
Thursday is the deadline for the assignment, so I have to get my arse in gear and finish it now.
The meeting is about to happen, so you'd better get your arse in gear,
To start working on something seriously or determinedly; to start doing what needs to be done
To start getting moving.
The verb "get" should be conjugated according to its tense.
Rainy, wet weather
It has been raining for hours, it is the season of lovely weather for ducks after all.