privateer vs war vessel

privateer and war vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
privateer	Yes	No	No	No
war vessel	Yes	No	No	No

As nouns, war vessel is a hypernym of privateer; that is, war vessel is a word with a broader meaning than privateer:

privateer: a privately owned warship commissioned to prey on the commercial shipping or warships of an enemy nation
war vessel: a government ship that is available for waging war

Other hypernyms of privateer include combat ship, warship.

privateer (noun)	war vessel (noun)
a privately owned warship commissioned to prey on the commercial shipping or warships of an enemy nation	a government ship that is available for waging war
an officer or crew member of a privateer