ground rattler vs rattlesnake

ground rattler and rattlesnake both are nouns.

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

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

ground rattler: small pygmy rattlesnake
rattlesnake: pit viper with horny segments at the end of the tail that rattle when shaken

Other hypernyms of ground rattler include rattler.

ground rattler (noun)	rattlesnake (noun)
small pygmy rattlesnake	pit viper with horny segments at the end of the tail that rattle when shaken