cachalot vs black whale

cachalot and black whale both are nouns.

Word	Noun	Adjective	Verb	Adverb
cachalot	Yes	No	No	No
black whale	Yes	No	No	No

As nouns, cachalot and black whale are synonyms defined as:

cachalot and black whale: large whale with a large cavity in the head containing spermaceti and oil; also a source of ambergris

Other synonyms of cachalot include Physeter catodon, sperm whale.

cachalot (noun)	black whale (noun)
large whale with a large cavity in the head containing spermaceti and oil; also a source of ambergris	large whale with a large cavity in the head containing spermaceti and oil; also a source of ambergris
	small dark-colored whale of the Atlantic coast of the United States; the largest male acts as pilot or leader for the school