rattlesnake's master vs rattlesnake master

rattlesnake's master and rattlesnake master both are nouns.

Word	Noun	Adjective	Verb	Adverb
rattlesnake's master	Yes	No	No	No
rattlesnake master	Yes	No	No	No

As nouns, rattlesnake's master and rattlesnake master are synonyms defined as:

rattlesnake's master and rattlesnake master: coarse prickly perennial eryngo of United States thought to cure rattlesnake bite

Other synonyms of rattlesnake's master include button snakeroot, Eryngium yuccifolium.

rattlesnake's master (noun)	rattlesnake master (noun)
coarse prickly perennial eryngo of United States thought to cure rattlesnake bite	coarse prickly perennial eryngo of United States thought to cure rattlesnake bite