What is meant by saying a person is stuck up?

When someone is described as "stuck up," it typically means they have an arrogant or haughty attitude, often believing they are superior to others. This behavior can manifest as being snobbish, condescending, or excessively proud. Such individuals may show little interest in others or seem dismissive of those they consider beneath them. Overall, it conveys a sense of pretentiousness and lack of humility.