red drum vs redfish

red drum and redfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
red drum	Yes	No	No	No
redfish	Yes	No	No	No

As nouns, red drum and redfish are synonyms defined as:

red drum and redfish: large edible fish found off coast of United States from Massachusetts to Mexico

Other synonyms of red drum include channel bass, Sciaenops ocellatus.

red drum (noun)	redfish (noun)
large edible fish found off coast of United States from Massachusetts to Mexico	male salmon that has recently spawned
	large edible fish found off coast of United States from Massachusetts to Mexico
	North Atlantic rockfish