banded rattlesnake vs rattler

banded rattlesnake and rattler both are nouns.

Word	Noun	Adjective	Verb	Adverb
banded rattlesnake	Yes	No	No	No
rattler	Yes	No	No	No

As nouns, rattler is a hypernym of banded rattlesnake; that is, rattler is a word with a broader meaning than banded rattlesnake:

banded rattlesnake: widely distributed in rugged ground of eastern United States
rattler: pit viper with horny segments at the end of the tail that rattle when shaken

Other hypernyms of banded rattlesnake include rattlesnake.

banded rattlesnake (noun)	rattler (noun)
widely distributed in rugged ground of eastern United States	pit viper with horny segments at the end of the tail that rattle when shaken
	a railroad train consisting of freight cars