Definition of shoot one's wad in English:

shoot one's wad

phrase

  • 1vulgar slang (of a man) ejaculate.

    • ‘I see bike companies and other sponsors shoot their wad for road season and have nothing to invest come winter.’
  • 2informal Do all that one can.

Origin

Originally, to fire one's gun with only the wad for a projectile when one's ammunition is exhausted.