of a sudden
    adv 1: happening unexpectedly; "suddenly she felt a sharp pain
           in her side" [syn: suddenly, all of a sudden, of a
           sudden]

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

            He withdrew his opposition all of a sudden.
                                                  --Thackeray.
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