The Collaborative International Dictionary of English v.0.48:

Wait \Wait\, v. i. [imp. & p. p. Waited; p. pr. & vb. n.
   Waiting.] [OE. waiten, OF. waitier, gaitier, to watch,
   attend, F. guetter to watch, to wait for, fr. OHG. wahta a
   guard, watch, G. wacht, from OHG. wahh[=e]n to watch, be
   awake. [root]134. See Wake, v. i.]
   [1913 Webster]
   1. To watch; to observe; to take notice. [Obs.]
      [1913 Webster]

            "But [unless] ye wait well and be privy,
            I wot right well, I am but dead," quoth she.
                                                  --Chaucer.
      [1913 Webster]

   2. To stay or rest in expectation; to stop or remain
      stationary till the arrival of some person or event; to
      rest in patience; to stay; not to depart.
      [1913 Webster]

            All the days of my appointed time will I wait, till
            my change come.                       --Job xiv. 14.
      [1913 Webster]

            They also serve who only stand and wait. --Milton.
      [1913 Webster]

            Haste, my dear father; 't is no time to wait.
                                                  --Dryden.
      [1913 Webster]
      [1913 Webster]

   To wait on or To wait upon.
      (a) To attend, as a servant; to perform services for; as,
          to wait on a gentleman; to wait on the table.
          "Authority and reason on her wait." --Milton. "I must
          wait on myself, must I?" --Shak.
      (b) To attend; to go to see; to visit on business or for
          ceremony.
      (c) To follow, as a consequence; to await. "That ruin that
          waits on such a supine temper." --Dr. H. More.
      (d) To look watchfully at; to follow with the eye; to
          watch. [R.] "It is a point of cunning to wait upon him
          with whom you speak with your eye." --Bacon.
      (e) To attend to; to perform. "Aaron and his sons . . .
          shall wait on their priest's office." --Num. iii. 10.
      (f) (Falconry) To fly above its master, waiting till game
          is sprung; -- said of a hawk. --Encyc. Brit.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Waiting \Wait"ing\,
   a. & n. from Wait, v.
   [1913 Webster]

   In waiting, in attendance; as, lords in waiting. [Eng.]

   Waiting gentlewoman, a woman who waits upon a person of
      rank.

   Waiting maid, Waiting woman, a maid or woman who waits
      upon another as a personal servant.
      [1913 Webster]

WordNet (r) 3.0 (2006):

waiting
    adj 1: being and remaining ready and available for use; "waiting
           cars and limousines lined the curb"; "found her mother
           waiting for them"; "an impressive array of food ready and
           waiting for the guests"; "military forces ready and
           waiting" [syn: waiting, ready and waiting(p)]
    n 1: the act of waiting (remaining inactive in one place while
         expecting something); "the wait was an ordeal for him"
         [syn: wait, waiting]

Moby Thesaurus II by Grady Ward, 1.0:

93 Moby Thesaurus words for "waiting":
   about to be, agape, agog, all agog, already in sight, anticipant,
   anticipating, anticipative, anticipatory, anxiety, apprehension,
   approaching, at hand, attendant, attending, awaiting, brewing,
   certain, cliff-hanging, close, close at hand, coming, confident,
   dalliance, dallying, dawdling, dillydallying, dread, eager,
   expectant, expectant waiting, expecting, forearmed, forestalling,
   forewarned, forthcoming, future, gaping, gathering,
   going to happen, helping, hopeful, immediate, imminent, impendent,
   impending, in anticipation, in danger imminent, in expectation,
   in prospect, in reserve, in store, in the cards, in the offing,
   in the wind, in view, instant, lingering, looking for,
   looking forward to, looming, lowering, lurking, menacing, menial,
   ministering, near, near at hand, nearing, not surprised,
   on the horizon, optimistic, overhanging, pessimism, prepared,
   preparing, ready, sanguine, servile, serving, servitorial, sure,
   suspense, tarriance, tarrying, that will be, threatening, to come,
   uncertainty, unsurprised, upcoming, waiting for, watching for