pee one's pants

verb3

1. •
   (informal) To wet oneself; to urinate in one's clothes while wearing them.

   • (Marvin) I'm so excited about Christmas being less than a week away, I could pee my pants! (Bitsy) Exactly how is that different than any other time? — 2015
2. •
   (informal) To laugh uncontrollably.
3. •
   (informal) To be extremely frightened.