Cave | ˈkāv
noun

1
: natural chamber or series of chambers in the earth, usually found on the side of a hill or cliff, or underground, and that is large enough for human exploration. 
2
: a chamber for storage that is usually underground.
3
: a place providing privacy or seclusion from others.

Cave | ˈkāv
verb

1
: to form a cave in or under (transitive)
: to explore caves especially as a sport or hobby (intransitive)
2
: to agree to something that you would not agree to before, after someone has persuaded you or threatened you : “to give in” (intransitive)
3
: to cease to resist : SUBMIT (intransitive)
: to cause to fall or collapse (transitive)

Caving | Cav·ing | ˈkāviNG
noun

1: recreational activity of exploring wild cave systems
: SPELUNKING (United States and Canada)
: POTHOLING (United Kingdom and Ireland)

Definitions were compiled from the following sources: Britannica, Cambridge, Merriam-Webster, Wikipedia