leatherjack vs leatherjacket

leatherjack and leatherjacket both are nouns.

Word	Noun	Adjective	Verb	Adverb
leatherjack	Yes	No	No	No
leatherjacket	Yes	No	No	No

As nouns, leatherjack and leatherjacket are synonyms defined as:

leatherjack and leatherjacket: any of several New World tropical fishes having tiny embedded scales

leatherjack (noun)	leatherjacket (noun)
any of several New World tropical fishes having tiny embedded scales	any of several brightly colored tropical filefishes
	any of several New World tropical fishes having tiny embedded scales
	tough-skinned larva of certain crane flies