1.
see stand 1, 2
2.
If something such as a claim or a piece of evidence stands up , it is accepted as true or satisfactory after being carefully examined.
He made wild accusations that did not stand up...
How well does this thesis stand up to close examination?
PHRASAL VERB : V P , V P to n
3.
If a boyfriend or girlfriend stands you up , they fail to keep an arrangement to meet you. ( INFORMAL )
We were to have had dinner together yesterday evening, but he stood me up...
PHRASAL VERB : V n P