helicopter vs whirlybird

helicopter and whirlybird both are nouns.

Word	Noun	Adjective	Verb	Adverb
helicopter	Yes	No	No	No
whirlybird	Yes	No	No	No

As nouns, helicopter and whirlybird are synonyms defined as:

helicopter and whirlybird: an aircraft without wings that obtains its lift from the rotation of overhead blades

Other synonyms of helicopter include chopper, eggbeater.

helicopter (noun)	whirlybird (noun)
an aircraft without wings that obtains its lift from the rotation of overhead blades	an aircraft without wings that obtains its lift from the rotation of overhead blades