Disdainful means showing contempt or scorn for something you think is beneath you or unworthy of respect. When someone looks at you with a disdainful expression, their face shows they think they're better than you or that what you're doing doesn't matter.

You might see disdain in a snobby character in a story who refuses to sit with certain kids at lunch, wrinkling their nose as if something smells bad. A disdainful tone of voice drips with superiority: imagine someone saying, “Oh, you still play with those toys?” in a way that makes you feel small.

The feeling comes from believing something or someone is inferior or not worth your attention. A student might be disdainful of a classmate's answer, rolling their eyes instead of listening respectfully. A chess champion might show disdain for easier games, acting as if they're too simple to be worth bothering with.