v.1. To rise to an upright position on the feet: When the judge entered the room, everyone stood up.
2. To cause something or someone to assume an upright position: I stood up the book on its end. The police tried to stand the drunken drivers up on their feet.
3. To remain valid, sound, or durable: The claim will not stand up in court. Our old car has stood up well over time.
4. To fail to keep a date or appointment with someone: My roommate stood up the prospective students who had wanted to tour the campus. My blind date stood me up, so I had to eat alone.
5. stand up for To defend or support someone or something: If you do not stand up for yourself, people will not respect you. The candidate stood up for the rights of migrant workers.
6. stand up to To confront someone or something fearlessly: The citizens were too afraid to stand up to the cruel dictator.
7. stand up with To act as best man, maid of honor, or matron of honor for some groom or bride at a wedding: I stood up with my old college roommate when he got married. She stood up with her sister at the wedding.