Fit/ready to drop - Idioms by The Free Dictionary
fit/ready to drop
fit to drop
Completely exhausted, fatigued, or worn out. I was fit to drop after only the first mile of the race; I could barely even walk for the rest of it!
fit (or ready) to drop worn out; exhausted.
fit/ready to ˈdrop (informal) very tired; exhausted: I feel fit to drop. ♢ We danced until we were ready to drop.