drop off vs unload

drop off and unload both are verbs.

Word	Noun	Adjective	Verb	Adverb
drop off	No	No	Yes	No
unload	No	No	Yes	No

As verbs, drop off and unload are synonyms defined as:

Other synonyms of drop off include discharge, drop, put down, set down.

drop off (verb)	unload (verb)
change from a waking to a sleeping state	remove the load from (a container or vehicle)
fall to a lower standard	remove (cargo, people, etc.) from and leave
fall or diminish
retreat
remove (cargo, people, etc.) from and leave