pen up vs confine

pen up and confine both are verbs.

Word	Noun	Adjective	Verb	Adverb
pen up	No	No	Yes	No
confine	No	No	Yes	No

As verbs, confine is a hypernym of pen up; that is, confine is a word with a broader meaning than pen up:

pen up: confine in a fold, like sheep
confine: to close within bounds, or otherwise limit or deprive of free movement

Other hypernyms of pen up include constrain, hold, restrain.

pen up (verb)	confine (verb)
confine in a fold, like sheep	place limits on (extent or amount or access)
	to close within bounds, or otherwise limit or deprive of free movement
	prevent from leaving or from being removed
	deprive of freedom; take into confinement
	close in