drop off—
1. become detached:
- The handle of the door has dropped off.
2. become abruptly much lower:
- The cliff drops off suddenly here, be careful.
3. (coll.) leave a vehicle; get off:
- Thanks for the ride, I’ll drop off here.
4. become less; deteriorate:
- The quality of performance has dropped off since last year.
5. (coll.) fall asleep:
- I went to bed early but for some reason I couldn’t drop off.
6. (euph.) die:
- He would probably drop off quietly with suppressed gout.
fall off—
1. = drop off 1:
- My top button has fallen off.
2. = drop off 2:
- The land falls off here towards the river.
3. = drop off 4:
- Their enthusiasm seems to be falling off a bit.
4. cease participation:
- Some of our most loyal members have now fallen off.