holding paddock vs holding pen

holding paddock and holding pen both are nouns.

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

As nouns, holding paddock and holding pen are synonyms defined as:

holding paddock and holding pen: a pen where livestock is temporarily confined

Other synonyms of holding paddock include holding yard.

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