pen vs holding paddock

pen and holding paddock both are nouns.

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

As nouns, holding paddock is a hyponym of pen; that is, holding paddock is a word with a more specific, narrower meaning than pen:

pen (noun)	holding paddock (noun)
female swan	a pen where livestock is temporarily confined
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

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