stand (so) up definition
Remain valid, sound, or durable, as in His claim will not stand up in court, or Our old car stood up well over time. [Mid-1900s]
Fail to keep a date or appointment with, as in Al stood her up twice in the past week, and that will be the end of their relationship. [Colloquial; c. 1900] Also see stand up for; stand up to; stand up with.