noon vs noontime

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 

noontime

noun
  • The time at which something peaks in some way (e.g., in vitality, in influence, in reknown) (by analogy with the waxing of the sun each day). 

  • Approximately noon. 

  • Noon. 

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