afternoon vs lunchtime

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. 

lunchtime

noun
  • The time or hour at or around which lunch is normally eaten. 

  • A break in work or school to eat lunch. 

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