attack aircraft vs warplane

attack aircraft and warplane both are nouns.

Word	Noun	Adjective	Verb	Adverb
attack aircraft	Yes	No	No	No
warplane	Yes	No	No	No

As nouns, warplane is a hypernym of attack aircraft; that is, warplane is a word with a broader meaning than attack aircraft:

attack aircraft: a high-speed military or naval airplane designed to destroy enemy aircraft in the air
warplane: an aircraft designed and used for combat

Other hypernyms of attack aircraft include aeroplane, airplane, plane, military plane.

attack aircraft (noun)	warplane (noun)
a high-speed military or naval airplane designed to destroy enemy aircraft in the air	an aircraft designed and used for combat