be out for blood

be out for blood

To seek vengeance in an especially hostile or belligerent manner. This phrase is often used hyperbolically, although it can refer to physical violence. I'd avoid the boss if I were you—he's out for blood and screaming at everyone he sees. Some neighborhood kids beat me up last night, and now my brother is out for blood.
See also: blood, out
Farlex Dictionary of Idioms.
See also:
  • be out for/after (one's) scalp
  • scalp
  • out for blood
  • (one's) head on a plate/platter
  • be a fate worse than death
  • beat off
  • and his mother
  • chance of a lifetime
  • can't get over (something)
  • can't get over something