sitting duck vs victim

sitting duck and victim both are nouns.

Word	Noun	Adjective	Verb	Adverb
sitting duck	Yes	No	No	No
victim	Yes	No	No	No

As nouns, victim is a hypernym of sitting duck; that is, victim is a word with a broader meaning than sitting duck:

Other hypernyms of sitting duck include dupe.

sitting duck (noun)	victim (noun)
a defenseless victim	an unfortunate person who suffers from some adverse circumstance
	a person who is tricked or swindled