pooh-pooh vs scorn

pooh-pooh is not a noun while scorn is a noun.

Word	Noun	Adjective	Verb	Adverb
pooh-pooh	No	No	Yes	No
scorn	Yes	No	Yes	No

As verbs, pooh-pooh and scorn are synonyms defined as:

Other synonyms of pooh-pooh include disdain, freeze off, reject, spurn, turn down.

pooh-pooh (noun)	scorn (noun)
	open disrespect for a person or thing
	lack of respect accompanied by a feeling of intense dislike

pooh-pooh (verb)	scorn (verb)
reject with contempt	reject with contempt
express contempt about	look down on with disdain