twin-aisle airplane vs airliner

twin-aisle airplane and airliner both are nouns.

Word	Noun	Adjective	Verb	Adverb
twin-aisle airplane	Yes	No	No	No
airliner	Yes	No	No	No

As nouns, airliner is a hypernym of twin-aisle airplane; that is, airliner is a word with a broader meaning than twin-aisle airplane:

twin-aisle airplane (noun)	airliner (noun)
a commercial airliner with two aisles	a commercial airplane that carries passengers