struggle vs grappling

struggle and grappling both are nouns.

Word	Noun	Adjective	Verb	Adverb
struggle	Yes	No	Yes	No
grappling	Yes	No	No	No

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

Other hyponyms of struggle include grapple, hand-to-hand struggle, wrestle, wrestling.

struggle (noun)	grappling (noun)
strenuous effort	the act of engaging in close hand-to-hand combat
an energetic attempt to achieve something	the sport of hand-to-hand struggle between unarmed contestants who try to throw each other down
an open clash between two opposing groups (or individuals)

struggle (verb)	grappling (verb)
be engaged in a fight; carry on a fight
to exert strenuous effort against opposition
climb awkwardly, as if by scrambling
make a strenuous or labored effort