bleeder

Short definition from Wiktionary

Noun

1. 1
   A person who is easily made to bleed, or who bleeds in unusually large amounts, particularly a hemophiliac.
2. 2
   A blood vessel that requires cauterization etc. to stop it from bleeding during surgery.
3. 3
   Anything that saps a resource produced by something else.
4. 4
   A valve designed to release a small amount of excess pressure from a system.
5. 5
   A troublesome fellow or thing; a blighter.
6. 6
   Synonym of scratch hit.
7. 7
   A person who menstruates (used in the context of transgender inclusivity).