preconceived idea vs sentiment

preconceived idea and sentiment both are nouns.

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

As nouns, sentiment is a hypernym of preconceived idea; that is, sentiment is a word with a broader meaning than preconceived idea:

preconceived idea: an opinion formed beforehand without adequate evidence
sentiment: a personal belief or judgment that is not founded on proof or certainty

Other hypernyms of preconceived idea include opinion, persuasion, thought, view.

preconceived idea (noun)	sentiment (noun)
an opinion formed beforehand without adequate evidence	a personal belief or judgment that is not founded on proof or certainty
	tender, romantic, or nostalgic feeling or emotion