holding paddock vs pen

holding paddock and pen both are nouns.

Word	Noun	Adjective	Verb	Adverb
holding paddock	Yes	No	No	No
pen	Yes	No	Yes	No

As nouns, pen is a hypernym of holding paddock; that is, pen is a word with a broader meaning than holding paddock:

holding paddock (noun)	pen (noun)
a pen where livestock is temporarily confined	female swan
	a writing implement with a point from which ink flows
	an enclosure for confining livestock
	a correctional institution for those convicted of major crimes
	a portable enclosure in which babies may be left to play

holding paddock (verb)	pen (verb)
	produce a literary work