setoff vs set-back

setoff and set-back both are nouns.

Word	Noun	Adjective	Verb	Adverb
setoff	Yes	No	No	No
set-back	Yes	No	No	No

As nouns, setoff and set-back are synonyms defined as:

setoff and set-back: structure where a wall or building narrows abruptly

Other synonyms of setoff include offset.

setoff (noun)	set-back (noun)
structure where a wall or building narrows abruptly	structure where a wall or building narrows abruptly