catamount vs mountain lion

catamount and mountain lion both are nouns.

Word	Noun	Adjective	Verb	Adverb
catamount	Yes	No	No	No
mountain lion	Yes	No	No	No

As nouns, catamount and mountain lion are synonyms defined as:

Other synonyms of catamount include cougar, Felis concolor, painter, panther, puma.

catamount (noun)	mountain lion (noun)
large American feline resembling a lion	large American feline resembling a lion
short-tailed wildcats with usually tufted ears; valued for their fur