French leave vs hooky

French leave

noun
  • Synonym of AWOL: absence from military service without permission, especially temporary shirking of duty subject to punishment. 

  • to take a French leave 

  • A departure taken suddenly, without announcement, and/or without permission. 

hooky

noun
  • Absence from school or work; truancy. 

adj
  • Full of hooks (in any sense). 

  • Dodgy; crooked; illicit. 

  • Shaped like or resembling a hook; hooked. 

How often have the words French leave and hooky occurred in a corpus of books? (source: Google Ngram Viewer )