rough-legged hawk vs roughleg

rough-legged hawk and roughleg both are nouns.

Word	Noun	Adjective	Verb	Adverb
rough-legged hawk	Yes	No	No	No
roughleg	Yes	No	No	No

As nouns, rough-legged hawk and roughleg are synonyms defined as:

rough-legged hawk and roughleg: large hawk of the Northern Hemisphere that feeds chiefly on small rodents and is beneficial to farmers

Other synonyms of rough-legged hawk include Buteo lagopus.

rough-legged hawk (noun)	roughleg (noun)
large hawk of the Northern Hemisphere that feeds chiefly on small rodents and is beneficial to farmers	large hawk of the Northern Hemisphere that feeds chiefly on small rodents and is beneficial to farmers