body louse vs cootie

body louse

noun
  • A parasitic insect, Pediculus humanus humanus (syn. Pediculus humanus corporis), that infests the body and clothes of humans and feeds on blood. 

cootie

noun
  • A louse (Pediculus humanus). 

  • Any germ or contaminant, real or imagined, especially from the opposite gender (for pre-pubescent children). 

  • A sideswiper, a type of telegraph key. 

  • A nest-building female American coot (counterpart to cooter). 

How often have the words body louse and cootie occurred in a corpus of books? (source: Google Ngram Viewer )