sportfishing vs casting

sportfishing and casting both are nouns.

Word	Noun	Adjective	Verb	Adverb
sportfishing	Yes	No	No	No
casting	Yes	No	No	No

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

sportfishing: the act of someone who fishes as a diversion
casting: the act of throwing a fishing line out over the water by means of a rod and reel

Other hyponyms of sportfishing include angling, cast.

sportfishing (noun)	casting (noun)
the act of someone who fishes as a diversion	the act of creating something by casting it in a mold
	the act of throwing a fishing line out over the water by means of a rod and reel
	the choice of actors to play particular roles in a play or movie
	object formed by a mold