Lunch is a meal eaten around the middle of the day. It is commonly the second meal of the day, after breakfast, but before dinner, and varies in size by culture and region. Etymology. According to the Oxford English Dictionary (OED), the etymology of lunch is uncertain. It may have evolved from lump in a similar way to hunch, a derivative of hump, and bunch, a derivative of bump. Alternatively, it may have evolved from the Spanish lonja, meaning 'slice of ham'. It was first recorded in 1591 with the meaning 'thick piece, hunk' as in "lunch of bacon".
https://en.wikipedia.org/wiki/Lunch