Prejudice (noun)

1. An irrational attitude of hostility directed against an individual, a group, a race, or their supposed characteristics.
2. An unfavorable opinion or feeling formed beforehand or without knowledge, thought, or reason.
3. An preconceived opinion that is not based on reason or actual experience.

Origin:

From old french prejudice ("injustice, harm"), from latin praeiudicium ("judgment formed in advance"), from prae ("before") + iudicium ("judgmen.t")

Examples:

1. He had a prejudice against people from that country.
2. She was not a victim of prejudice, but of discrimination.
3. The decision was based on prejudice, not on facts.
4. He had a prejudice against people with tattoos.
5. The prejudice against women in the workplace is still prevalent.