accidental adventitious aleatory arguable at issue capricious casual causeless chance chancy confutable conjectural contestable contingent controversial controvertible debatable deniable destinal dicey disputable doubtable doubtful dubious dubitable erratic fatal fatidic fluctuant fluky fortuitous in dispute in doubt in dubio in question incalculable incidental indeterminate mistakable moot open to doubt open to question problematic questionable refutable risky speculative suppositional suspect suspicious uncaused undetermined unexpected unforeseeable unforeseen unlooked-for unpredictable whimsical