set down vs unload

set down and unload both are verbs.

Word	Noun	Adjective	Verb	Adverb
set down	No	No	Yes	No
unload	No	No	Yes	No

As verbs, set down and unload are synonyms defined as:

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

set down (verb)	unload (verb)
put down in writing; of texts, musical compositions, etc.	remove the load from (a container or vehicle)
remove (cargo, people, etc.) from and leave	remove (cargo, people, etc.) from and leave
put or settle into a position
cause to sit or seat or be in a settled position or place
go ashore
reach or come to rest