shake a leg

基本解释

Shake a leg， they’re getting impatient.
快动身吧，他们已经等得不耐烦了。
Let's shake a leg there, you guys! I got to get this truck unloaded and on the way back to the warehouse before dark.
他说：“喂！你们这帮人快点儿吧！我得把这车货卸完，在天黑前赶回仓库去呢。”
3：Bob! Hey, Bob, wake up! It's already 9:30 and you've got that big math test at 10 o'clock. Come on, man, shake a leg! Come on, - you've got to get moving right now!
他使劲叫醒Bob，因为已经到九点半了，而Bob十点有数学大测验。时间紧迫，所以他要Bob必须立刻行动起来。显然他说shake a leg，是催促Bob赶快行动。这就是这个习惯用语的意思。