afternoon vs noontime

afternoon

noun
  • The part of the day from noon or lunchtime until sunset, evening, or suppertime or 6pm. 

  • The later part of anything, often with implications of decline. 

  • A party or social event held in the afternoon. 

noontime

noun
  • Approximately noon. 

  • 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). 

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