crottal vs crottle

crottal and crottle both are nouns.

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

As nouns, crottal and crottle are synonyms defined as:

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

Other synonyms of crottal include crotal.

crottal (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