#1 drop off v. fall or diminish; "The number of students in this course dropped off after the first test". wn
#2 drop off v. change from a waking to a sleeping state; "he always falls asleep during lectures". wn
#3 drop off v. leave or unload; "unload the cargo"; "drop off the passengers at the hotel". wn
#4 drop off v. retreat. wn
#5 drop off v. get worse; "My grades are slipping". wn
vizzz