sudden

sudden
    adj 1: happening without warning or in a short space of time; "a
           sudden storm"; "a sudden decision"; "a sudden cure" [ant:
           {gradual}]
    

Sudden \Sud"den\, a. [OE. sodian, sodein, OF. sodain, sudain, F.
   soudain, L. subitaneus, fr. subitus sudden, that has come
   unexpectedly, p. p. of subire to come on, to steal upon; sub
   under, secretly + ire to go. See {Issue}, and cf.
   {Subitaneous}.]
   1. Happening without previous notice or with very brief
      notice; coming unexpectedly, or without the common
      preparation; immediate; instant; speedy. "O sudden wo!"
      --Chaucer. "For fear of sudden death." --Shak.
      [1913 Webster]

            Sudden fear troubleth thee.           --Job xxii.
                                                  10.
      [1913 Webster]

   2. Hastly prepared or employed; quick; rapid.
      [1913 Webster]

            Never was such a sudden scholar made. --Shak.
      [1913 Webster]

            The apples of Asphaltis, appearing goodly to the
            sudden eye.                           --Milton.
      [1913 Webster]

   3. Hasty; violent; rash; precipitate. [Obs.] --Shak.
      [1913 Webster]

   Syn: Unexpected; unusual; abrupt; unlooked-for.
        [1913 Webster] -- {Sud"den*ly}, adv. -- {Sud"den*ness},
        n.
        [1913 Webster]
    

Sudden \Sud"den\, adv.
   Suddenly; unexpectedly. [R.]
   [1913 Webster]

         Herbs of every leaf that sudden flowered. --Milton.
   [1913 Webster]
    

Sudden \Sud"den\, n.
   An unexpected occurrence; a surprise.
   [1913 Webster]

   {All of a sudden}, {On a sudden}, {Of a sudden}, sooner than
      was expected; without the usual preparation; suddenly.
      [1913 Webster]

            How art thou lost! how on a sudden lost! --Milton.
      [1913 Webster]

            He withdrew his opposition all of a sudden.
                                                  --Thackeray.
      [1913 Webster]
    

60 Moby Thesaurus words for "sudden":
      aback, abrupt, abruptly, accelerated, breakneck, breathless, brisk,
      electrifying, expeditious, extraordinary, fast, fleet, forthwith,
      hasty, headlong, hurried, immediate, impatient, impetuous,
      improbable, impulsive, more than expected, nerve-shattering,
      out-of-the-way, overhasty, panting, past expectation, precipitant,
      precipitate, precipitous, quick, rapid, rash, reckless, rushing,
      shocking, short, speedy, startling, suddenly, surprising, swift,
      unannounced, unanticipated, unanticipatedly, unaware, undivined,
      unexpected, unexpectedly, unforeseeable, unforeseen, unguessed,
      unheralded, unhoped for, unlooked-for, unpredictable, unpredicted,
      unprepared for, unwonted, without warning