Lunch or Luncheon.
There has been much questioning as to the distinction between the words "lunch" and "luncheon," which are often used interchangeably. The latest and best definition would be, that a lunch is a meal to be partaken of informally by the members of a household, at midday or before going on some pleasure excursion. Luncheon, on the contrary, signifies a form of entertainment given after breakfast and before the evening dinner hour. It is a meal of compliment and more frequently extended to ladies alone.
The invitations given for a luncheon are issued on the same principle as those for a breakfast. A young performer, vocalist or elocutionist, is often introduced at a luncheon.