definition of leech
Leech (noun) any one of numerous genera and species of annulose worms, belonging to the order Hirudinea, or Bdelloidea, esp. those species used in medicine, as Hirudo medicinalis of Europe, and allied species. Leech (noun) a glass tube of peculiar construction, adapted for drawing blood from a scarified part by means of a vacuum. Leech (verb) to treat as a surgeon; to doctor; as, to leech wounds. Leech (verb) to bleed by the use of leeches