1. To be in or arise into a standing position. I hope we don't have to stand up for much longer, my legs are getting tired. Tom, please stand up and tell the class about your vacation.

2. To pull or place someone or something into a standing or upright position. In this usage, a noun or pronoun can be used between "stand" and "up." After I fell, my teacher stood me up and brushed off my jacket. OK, the bookshelf has been assembled. Let's stand it up and move it against the wall.

3. To fail to meet someone for a date, meeting, or appointment, especially without telling them. In this usage, a noun or pronoun can be used between "stand" and "up." I'm sorry I stood you up, but I had a family emergency last night. Tom is really bad about standing up his dates.

4. To remain or prove to be valid, credible, or defensible. The video definitely makes him look suspicious, but it wouldn't stand up in court. I just don't think her early work stands up in comparison to her modern masterpieces.

5. To have durability and longevity; to last over time. We've had this car for nearly 20 years, and it still stands up. It looks slick, but it won't stand up to the extreme conditions of the local environment.