drain the main vein

drain the main vein

vulgar slang Of a male, to urinate. "Main vein" is slang for the penis. Will you order us another round of drinks? I'm just going to go drain the main vein real quick.
See also: drain, main
Farlex Dictionary of Idioms.
See also:
  • main
  • branch off
  • by main force
  • (one's)/the main squeeze
  • be (one's)/the main squeeze
  • someone's main squeeze
  • be somebody's life
  • be (one's) life
  • go straight
  • go straight, to