overnight bag vs valise

overnight bag and valise both are nouns.

Word	Noun	Adjective	Verb	Adverb
overnight bag	Yes	No	No	No
valise	Yes	No	No	No

As nouns, valise is a hyponym of overnight bag; that is, valise is a word with a more specific, narrower meaning than overnight bag:

overnight bag: a small traveling bag to carry clothing and accessories for staying overnight
valise: a small overnight bag for short trips

overnight bag (noun)	valise (noun)
a small traveling bag to carry clothing and accessories for staying overnight	a small overnight bag for short trips