shake a leg—(coll.)
1. move faster; hurry up:
- They are waiting outside in the car; let’s shake a leg!
2. dance:
- The stage is ready for them, if they like to act or the dancing-room, should they wish to shake a leg.
Note: The expression does not correlate in meaning with the phrase swing the leg—(Nautical) evade duty:
- There was a nautical expression “swing the leg,” an allusion to the pretence of having a damaged leg so as to avoid work.
shake a loose leg—(rare)
1. = shake a leg 2:
- Play, for Heaven’s sake, or you will work yourselves into a nation of automatons! Shake a loose leg to a lively fiddle!
2. (coll.) lead an irregular life; live freely:
- You’re too much occupied here with your shop: besides, you may shake a loose leg yourself occasionally for all the public knows, eh?