exit vs leaving

exit and leaving both are nouns.

Word	Noun	Adjective	Verb	Adverb
exit	Yes	No	Yes	No
leaving	Yes	No	No	No

As nouns, leaving is a hypernym of exit; that is, leaving is a word with a broader meaning than exit:

Other hypernyms of exit include departure, going, going away.

exit (noun)	leaving (noun)
the act of going out	the act of departing
an opening that permits escape or release
euphemistic expressions for death

exit (verb)	leaving (verb)
pass from physical life and lose all bodily attributes and functions necessary to sustain life
lose the lead
move out of or depart from