sidewinder vs rattler

sidewinder and rattler both are nouns.

Word	Noun	Adjective	Verb	Adverb
sidewinder	Yes	No	No	No
rattler	Yes	No	No	No

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

sidewinder: small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve
rattler: pit viper with horny segments at the end of the tail that rattle when shaken

Other hypernyms of sidewinder include rattlesnake.

sidewinder (noun)	rattler (noun)
small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve	pit viper with horny segments at the end of the tail that rattle when shaken
air-to-air missile with infrared homing device	a railroad train consisting of freight cars