Well up has 3 different meanings across 1 category:
Verb
Verb
1
come up (as of feelings and thoughts, or other ephemeral things)
"Strong emotions welled up"
"Smoke swelled from it"
2
To gradually or steadily flow upwards or outwards so as to begin to fill or overflow something.
Adjective
1
Well versed; well acquainted (in or on).
Broader Terms (hypernyms)