bad blood

noun4

1. •
   Feelings of hostility or ill will.

   • The government at home, and the people of the colonies, are getting to have bad blood between them. — 1843
2. •
   A serious feud or long-standing grudge.
3. •
   (old-fashioned) An inherited immoral or disturbed nature.

   • [I]f we dare not search ourselves close enough to discover the low breeding, the bad blood in us, it will one day come out plain as the smitten brand of the forcat. — 1882
4. •
   A particular disease; in some places, syphilis.