grub vs leatherjacket

grub and leatherjacket both are nouns.

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

As nouns, leatherjacket is a hyponym of grub; that is, leatherjacket is a word with a more specific, narrower meaning than grub:

Other hyponyms of grub include maggot.

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

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