blackbuck vs black buck

blackbuck and black buck both are nouns.

Word	Noun	Adjective	Verb	Adverb
blackbuck	Yes	No	No	No
black buck	Yes	No	No	No

As nouns, blackbuck and black buck are synonyms defined as:

blackbuck and black buck: common Indian antelope with a dark back and spiral horns

Other synonyms of blackbuck include Antilope cervicapra.

blackbuck (noun)	black buck (noun)
common Indian antelope with a dark back and spiral horns	common Indian antelope with a dark back and spiral horns