napping vs off-guard

napping and off-guard both are adjectives.

Word	Noun	Adjective	Verb	Adverb
napping	No	Yes	No	No
off-guard	No	Yes	No	No

As adjectives, napping and off-guard are synonyms defined as:

Other synonyms of napping include off guard, off her guard, off his guard, off one's guard, off your guard.

napping (adjective)	off-guard (adjective)
not prepared or vigilant	not prepared or vigilant