directional vs flasher

directional

noun
  • Something that indicates direction, such as a vehicle's turn signal. 

adj
  • Indicating direction. 

  • Of or relating to guidance or help. 

flasher

noun
  • An indicator or turn signal. 

  • Someone who exposes themselves indecently; someone who ‘flashes’ their genitals. 

  • Anything that flashes, especially a device that switches a light on and off. 

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