I mean, you could just look it up. In this case, the relevant definitions include "based on or causing prejudice - a bias or a preconceived opinion, idea, or belief about something" and "harmful, damaging, or causing disadvantage to someone or something."
But hey, not wanting to learn is consistent with the flagged comment you posted earlier. Simple refutation of your point: do you really think that there's no woman who could have done a better job as US president over the last couple of years? Maybe someone who knows what "prejudicial" means, or is capable of looking it up?
When your thought process is corrupted by bigotry, you ignore differences in individual attributes and capabilities, both within groups that you're biased against, as well as in the groups that you identify with. (Side note, this is classic identity politics, so if you've ever railed against that, you might want to check a mirror.)
It's essentially the way that primitive tribespeople thought and behaved thousands of years ago, but some people seem unable to overcome that irrationality, even with the benefit of education.
