sailing vs hang gliding

sailing and hang gliding both are nouns.

Word	Noun	Adjective	Verb	Adverb
sailing	Yes	No	No	No
hang gliding	Yes	No	No	No

As nouns, hang gliding is a hyponym of sailing; that is, hang gliding is a word with a more specific, narrower meaning than sailing:

Other hyponyms of sailing include paragliding, parasailing.

sailing (noun)	hang gliding (noun)
riding in a sailboat	gliding in a hang glider
the work of a sailor
the departure of a vessel from a port
the activity of flying a glider