prejudice
definition
forming a judgment about somebody or something that is not based on reason or experience
example
Janice feared her parents' prejudice against same-sex couples would make them disapprove of her relationship with Melissa.
synonyms
biasinjusticepreconception
word origin — Middle English (in prejudice (sense 2 of the noun)): from Old French, from Latin praejudicium, from prae ‘in advance’ + judicium ‘judgement’