preconception vs preconceived idea

preconception and preconceived idea both are nouns.

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

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

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

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

preconception (noun)	preconceived idea (noun)
an opinion formed beforehand without adequate evidence	an opinion formed beforehand without adequate evidence
a partiality that prevents objective consideration of an issue or situation