rattler vs diamondback

rattler and diamondback both are nouns.

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

As nouns, diamondback is a hyponym of rattler; that is, diamondback is a word with a more specific, narrower meaning than rattler:

rattler: pit viper with horny segments at the end of the tail that rattle when shaken
diamondback: large deadly rattlesnake with diamond-shaped markings

rattler (noun)	diamondback (noun)
pit viper with horny segments at the end of the tail that rattle when shaken	large deadly rattlesnake with diamond-shaped markings
a railroad train consisting of freight cars