Source : Webster's Revised Unabridged Dictionary (1913)

Dinner \Din"ner\, n. [F. d[^i]ner, fr. d[^i]ner to dine. See
   {Dine}.]
   1. The principal meal of the day, eaten by most people about
      midday, but by many (especially in cities) at a later
      hour.

   2. An entertainment; a feast.

            A grand political dinner.             --Tennyson.

   Note: Dinner is much used, in an obvious sense, either
         adjectively or as the first part of a compound; as,
         dinner time, or dinner-time, dinner bell, dinner hour,
         etc.

Source : WordNet®

dinner
     n 1: the main meal of the day served in the evening or at midday;
          "dinner will be at 8"; "on Sundays they had a large
          dinner when they returned from church"
     2: a party of people assembled to have dinner together; "guests
        should never be late to a dinner party" [syn: {dinner
        party}]