hold one's water

Verb

hold one's water (third-person singular simple present holds one's water, present participle holding one's water, simple past and past participle held one's water)

1. (dated) To restrain one's urge to urinate.
   • […] and if there is much oozing of blood, the application of ice to the penis. The patient is then instructed to hold his water as long as possible.1877, Shirley Bragg MD, “Structure of the Male Urethra, with Report of Cases,”, in Atlanta Medical and Surgical Journal, Volume 14, pages 645–6

   Synonyms:

   hold it

2. (idiomatic) To be patient; to control one's impulses.
   • Hold your water, I'll get to you in a minute.
   • "C'mon, move it! Get your ass in gear!" […]
     "Hold your water!" Stiehl yelled back. "I'm writing farewell letters."2011, Thomas Swan, chapter 1, in The Da Vinci Deception: An Inspector Jack Oxby Novel, →ISBN

   Synonyms:

   abide, back that train up, bide, bide one's time, expect, defer, hang on, hold on, hold one's breath, hold one's horses