prepossession vs preconceived idea

prepossession and preconceived idea both are nouns.

Word	Noun	Adjective	Verb	Adverb
prepossession	Yes	No	No	No
preconceived idea	Yes	No	No	No

As nouns, prepossession and preconceived idea are synonyms defined as:

prepossession and preconceived idea: an opinion formed beforehand without adequate evidence

Other synonyms of prepossession include parti pris, preconceived notion, preconceived opinion, preconception.

prepossession (noun)	preconceived idea (noun)
an opinion formed beforehand without adequate evidence	an opinion formed beforehand without adequate evidence
the condition of being prepossessed