Source : WordNet®

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}, {unlooked-for},
             {out of the blue(p)}]
     2: happening or coming quickly and without warning; "a sudden
        unexpected development" [syn: {unexpected}]