cargo helicopter vs chopper

cargo helicopter and chopper both are nouns.

Word	Noun	Adjective	Verb	Adverb
cargo helicopter	Yes	No	No	No
chopper	Yes	No	No	No

As nouns, chopper is a hypernym of cargo helicopter; that is, chopper is a word with a broader meaning than cargo helicopter:

cargo helicopter: a helicopter that carries cargo
chopper: an aircraft without wings that obtains its lift from the rotation of overhead blades

Other hypernyms of cargo helicopter include eggbeater, helicopter, whirlybird.

cargo helicopter (noun)	chopper (noun)
a helicopter that carries cargo	a grounder that bounces high in the air
	a butcher's knife having a large square blade
	an aircraft without wings that obtains its lift from the rotation of overhead blades
	informal terms for a human `tooth'