drop off

verb

1. 1

   change from a waking to a sleeping state

   he always falls asleep during lectures

2. 2

   fall or diminish

   The number of students in this course dropped off after the first test

3. 3

   get worse

   My grades are slipping

4. 4

   retreat

5. 5

   leave or unload

   unload the cargo

   drop off the passengers at the hotel