leatherjacket vs grub

leatherjacket and grub both are nouns.

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

As nouns, grub is a hypernym of leatherjacket; that is, grub is a word with a broader meaning than leatherjacket:

leatherjacket (noun)	grub (noun)
any of several brightly colored tropical filefishes	a soft thick wormlike larva of certain beetles and other insects
any of several New World tropical fishes having tiny embedded scales	informal terms for a meal
tough-skinned larva of certain crane flies

leatherjacket (verb)	grub (verb)
	search about busily
	ask for and get free; be a parasite