judge someone

偏見(へんけん)	A really strong, intentional prejudice. Not only do I not like your kind, but I know a lot of stereotypes about you. PPP

判断(はんだん)	To judge someone casually, like as you walk down the street and see a raver and think, “Stupid raver!” If you want to say, “I hate it when people judge me!” you’d use 判断 and not 偏見. SITU

先入観(せんにゅかん)	A preconception. As opposed to the strong, intentional prejudice of 偏見, 先入観 is a weak, ignorance-based prejudice. PPP

判決(はんけつ)	The official decision of a judge at a trial.

裁く(さばく)	Combines the meanings of ‘judge legally’ and ‘punish’ or ‘mete out justice to’. You wouldn’t use this about judging a pie-eating contest, but about a war-crimes tribunal or a lawsuit. PPP

審査(しんさ)	This is the one you’d use about a pie-eating contest. “The judges on American Idol.” As opposed to Supreme Court judges. 審査 can also be used for any exam, like when you get your car smogged, or when the meat inspector comes to your butcher shop. PPP