The Collaborative International Dictionary of English v.0.48:

Dining \Din"ing\, n. & a.
   from Dine, a.
   [1913 Webster]

   Note: Used either adjectively or as the first part of a
         compound; as, dining hall or dining-hall, dining room,
         dining table, etc.
         [1913 Webster] dining-hall
         dininghall

The Collaborative International Dictionary of English v.0.48:

Dine \Dine\, v. i. [imp. & p. p. Dined; p. pr. & vb. n.
   Dining.] [F. d[^i]ner, OF. disner, LL. disnare, contr. fr.
   an assumed disjunare; dis- + an assumed junare (OF. juner) to
   fast, for L. jejunare, fr. jejunus fasting. See Jejune, and
   cf. Dinner, D?jeuner.]
   To eat the principal regular meal of the day; to take dinner.
   [1913 Webster]

         Now can I break my fast, dine, sup, and sleep. --Shak.
   [1913 Webster]

   To dine with Duke Humphrey, to go without dinner; -- a
      phrase common in Elizabethan literature, said to be from
      the practice of the poor gentry, who beguiled the dinner
      hour by a promenade near the tomb of Humphrey, Duke of
      Gloucester, in Old Saint Paul's.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dining
    n 1: the act of eating dinner