Barbary pirate vs sea rover

Barbary pirate and sea rover both are nouns.

Word	Noun	Adjective	Verb	Adverb
Barbary pirate	Yes	No	No	No
sea rover	Yes	No	No	No

As nouns, sea rover is a hypernym of Barbary pirate; that is, sea rover is a word with a broader meaning than Barbary pirate:

Barbary pirate: a pirate along the Barbary Coast
sea rover: someone who robs at sea or plunders the land from the sea without having a commission from any sovereign nation

Other hypernyms of Barbary pirate include buccaneer, pirate, sea robber.

Barbary pirate (noun)	sea rover (noun)
a pirate along the Barbary Coast	someone who robs at sea or plunders the land from the sea without having a commission from any sovereign nation