crotal vs crottle

crotal and crottle both are nouns.

Word	Noun	Adjective	Verb	Adverb
crotal	Yes	No	No	No
crottle	Yes	No	No	No

As nouns, crotal and crottle are synonyms defined as:

crotal and crottle: any of several lichens of the genus Parmelia from which reddish brown or purple dyes are made

Other synonyms of crotal include crottal.

crotal (noun)	crottle (noun)
any of several lichens of the genus Parmelia from which reddish brown or purple dyes are made	any of several lichens of the genus Parmelia from which reddish brown or purple dyes are made