1. 事先形成的看法；先入之见；成见
Your preconceptions about something are beliefs formed about it before you have enough information or experience.

1. an opinion formed beforehand without adequate evidence

e.g. he did not even try to confirm his preconceptions

Synonym: prepossessionparti prispreconceived opinionpreconceived ideapreconceived notion

2. a partiality that prevents objective consideration of an issue or situation

Synonym: biasprejudice