inscrutable /ˌɪnˈskɹuːtəbl̩/adjective 1noun 1forms 3 adjective1 •Difficult or impossible to comprehend, fathom, or interpret.His inscrutable theories would years later become the foundation of a whole new science. noun1 •One who or that which is inscrutable; a person, etc. that cannot be comprehended. formsinscrutables · more inscrutable · most inscrutable