cootie

noun4

1. •
   (informal, slang) A louse (Pediculus humanus).
2. •
   [usually plural] (US, informal) Any germ or contaminant, real or imagined, especially from the opposite gender (for pre-pubescent children).

   • I’m not drinking from his glass until I wash the cooties off it.
3. •
   (rare) A nest-building female American coot (counterpart to cooter).
4. •
   (slang, rare) A sideswiper, a type of telegraph key.