noontime vs undern

noontime

noun
  • Noon. 

  • Approximately noon. 

  • 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). 

undern

noun
  • Synonym of afternoon. 

  • A light meal, particularly in the afternoon. 

  • Synonym of evening. 

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