Prejudice can be an affective feeling towards a person based on their perceived group membership. The word is often used to refer to a preconceived (usually unfavourable) evaluation or classification of another person based on that person's perceived personal characteristics, such as political affiliation, sex, gender, gender identity, beliefs, values, social class, age, disability, religion, sexuality, race, ethnicity, language, nationality, culture, complexion, beauty, height, body weight, occupation, wealth, education, criminality, sport-team affiliation, music tastes or other perceived characteristics.

The word "prejudice" can also refer to unfounded or pigeonholed beliefs and it may apply to "any unreasonable attitude that is unusually resistant to rational influence". Gordon Allport defined prejudice as a "feeling, favorable or unfavorable, toward a person or thing, prior to, or not based on, actual experience". Auestad (2015) defines prejudice as characterized by "symbolic transfer", transfer of a value-laden meaning content onto a socially-formed category and then on to individuals who are taken to belong to that category, resistance to change, and overgeneralization.