Zip vs sill

Zip

noun
  • A Sicilian or Italian Mafioso who is relatively new to the United States. 

sill

noun
  • A young herring. 

  • The shaft or thill of a carriage. 

  • A stratum of rock, especially an intrusive layer of igneous rock lying parallel to surrounding strata. 

  • The inner edge of the bottom of an embrasure. 

  • A threshold; horizontal structural member of a building near ground level on a foundation or pilings, or lying on the ground, and bearing the upright portion of a frame; a sill plate. 

  • A threshold or brink across the bottom of a canal lock for the gates to shut against. 

  • A raised area at the base of the nasal aperture in the skull. 

  • A breast wall; window breast; horizontal brink which forms the base of a window. 

adj
  • Silly. 

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