bad seed

Noun

bad seed (usually uncountable, plural bad seeds)

1. (usually) A genetic source of bad behavior or other negative results.
   • A bad seed produces a bad tree and in due course bad fruit, and a good seed produces a good tree and good fruit.1533, Paracelsus, Paracelsus: Essential Readings, translation of Liber Prologi in Vitam Beatam by Nicholas Goodrick-Clarke, published 1999, page 147
   • In families that insist the child is different, the myth that prevails and perpetuates is the "bad seed theory." This becomes easier for families to do when the kids behave poorly and the only information they receive about the biological family are its problems and dysfunction2001, Victor Groza with Karen F. Rosenberg, Clinical and Practice Issues in Adoption, page 7
2. (usually) A bad apple: a bad person who negatively influences others.