incapable of being investigated, analyzed, or scrutinized; impenetrable.

not easily understood; mysterious; unfathomable

an inscrutable smile.

incapable of being seen through physically; physically impenetrable

the inscrutable depths of the ocean.

adjective

clear , comprehensible , evident , intelligible , obvious , plain

adjective

ambiguous , arcane , cabalistic , deadpan * , difficult , enigmatic , impenetrable , incomprehensible , inexplicable , mysterial , mystic , poker-faced * , secret , sphinxlike , unaccountable , undiscoverable , unexplainable , unfathomable , unintelligible , unknowable , unreadable , uncomprehensible , abstruse , baffling , blank , hidden , inexplainable , mysterious , unrevealing , unsearchable