pooh-pooh vs disdain

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

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

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

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

pooh-pooh (noun)	disdain (noun)
	a communication that indicates lack of respect by patronizing the recipient
	lack of respect accompanied by a feeling of intense dislike

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