unforeseen circumstances

unforeseen circumstances adjective atypical, different, exceptional, extraordinary, first, first ever, incomparable, matchless, never before encounnered, new, not to be expected, novel, of its own kind, off the beaten track, offbeat, original, out of the ordinary, out of the pale, out-of-the-way, rare, remarkable, sensational, singular, strange, surprising, tremendous, unaccustomed, uncommon, uncustomary, unequaled, unexampled, unfamiliar, unheard of, unique, unmatched, unprecedented, unthought-of, unusual