preconceived opinion vs preconception

preconceived opinion and preconception both are nouns.

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

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

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

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

preconceived opinion (noun)	preconception (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