1. 
[syn: unanticipated, unforeseen, unlooked-for, out of the blue(p)]
The Collaborative International Dictionary of English v.0.48:
Unforeseen \Unforeseen\
   See foreseen.
WordNet (r) 3.0 (2006):
unforeseen
    adj 1: not anticipated; "unanticipated and disconcerting lines
           of development"- H.W.Glidden; "unforeseen circumstances";
           "a virtue unlooked-for in people so full of energy";
           "like a bolt out of the blue" [syn: unanticipated,
           unforeseen, unlooked-for, out of the blue(p)]
Moby Thesaurus II by Grady Ward, 1.0:
57 Moby Thesaurus words for "unforeseen":
   abrupt, accidental, adventitious, aleatory, casual, causeless,
   chance, chancy, contingent, destinal, dicey, electrifying,
   extraordinary, fatal, fatidic, fluky, fortuitous, hasty, headlong,
   iffy, impetuous, improbable, impulsive, incidental, indeterminate,
   more than expected, nerve-shattering, out-of-the-way,
   past expectation, precipitant, precipitate, precipitous, quick,
   risky, shocking, speedy, startling, sudden, surprise, surprising,
   swift, unannounced, unanticipated, uncaused, undetermined,
   undivined, unexpected, unforeseeable, unguessed, unheralded,
   unhoped for, unlooked-for, unpredictable, unpredicted,
   unprepared for, unsought, without warning