You are on the right track with the word "judge". Now add the prefix "pre". which means "before". Put them together and you have the word "prejudice". This literally means "to judge before". This could be a prejudice about a person, an entire set of people based on any old thing, such as ethnicity or the color of their eyes or hair, Think of the assumptions that some people make about women with blonde hair, the holocaust of World War Two when Adolf Hitler and his minions did their level best to annihilate all people of the Jewish faith, or the treatment of Americans of Japanese descent during World War Two, and what you are looking at is prejudice. A person who makes these judgments is known as prejudicial.