insolvable Synonyms

unsolvable unsoluble unresolvable insoluble hopeless undecidable undecipherable nonsolvable unanalyzable unattainable undoable unsolved unable to be solved unfathomable unaccountable irresolvable impenetrable impossible inapprehensible incomprehensible indeterminable indissoluble inexplicable inextricable inscrutable insuperable irresoluble without a solution