noon vs sidereal day

noon

noun
  • The time of day when the sun is in its zenith; twelve o'clock in the day, midday. 

  • The highest point; culmination. 

  • The letter ن in the Arabic script. 

verb
  • To relax or sleep around midday 

sidereal day

noun
  • One day of sidereal time; the time in which Earth rotates once around its axis, relative to the point of the vernal equinox (about 23 hours, 56 minutes, 4 seconds). 

  • The rotational period of Earth; the time in which Earth rotates around its axis 360 degrees. 

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