luncher

noun

1. Someone who lunches; someone who eats lunch.

   “The knowledge of envy was a pleasant feeling to the man of no account. It was intensified later in the day when a luncher at the Club said, spitefully, “Well, for a debilitated Ditcher, Yeere, you are going it.””

   “Late lunchers had the pick of the menu.”

2. One who treats another person to lunch.

   “If the luncher, choose venue carefully, reconnoitre loos. If lunchee, be prompt, but not early.”