To dismiss something means to decide it's not worth your attention or consideration. When you dismiss an idea, you're essentially saying “no, that won't work” and moving on. A teacher might dismiss a wild excuse for missing homework, recognizing it as untrue. A scientist might dismiss a theory that contradicts clear evidence.

Dismiss also means to send someone away or end something officially. A judge dismisses a court case when there's no valid reason to continue it. A teacher dismisses the class at the end of the school day, releasing everyone to go home. A boss might dismiss an employee, which is a formal way of saying they're fired.

The word often carries a sense of finality and authority. When something is dismissed, it's done, over, not up for further debate. You might feel frustrated if someone dismisses your concerns without really listening, treating your worries as unimportant.

Sometimes what seems silly at first turns out to be brilliant. The Wright brothers' plan to build a flying machine was dismissed by many experts who were certain humans would never fly.