set down vs fill out

set down and fill out both are verbs.

Word	Noun	Adjective	Verb	Adverb
set down	No	No	Yes	No
fill out	No	No	Yes	No

set down (verb)	fill out (verb)
put down in writing; of texts, musical compositions, etc.	become round, plump, or shapely
remove (cargo, people, etc.) from and leave	make bigger or better or more complete
put or settle into a position	write all the required information onto a form
cause to sit or seat or be in a settled position or place	make fat or plump
go ashore	line or stuff with soft material
reach or come to rest	supplement what is thought to be deficient