incapable /ɪnˈkeɪpəbl̩/adjective 2noun 1forms 3 adjective2 •Not capable (of doing something); unable.A pint glass is incapable of holding more than a pint of liquid.I consider him incapable of dishonesty. •Not in a state to receive; not receptive; not susceptible; not able to admit. noun1 •(old-fashioned) One who is morally or mentally weak or inefficient; an imbecile; a simpleton. formsincapables · more incapable · most incapable