prosthetic UK /ˌpɹɒsˈθɛtɪk/US /ˌpɹɑsˈθɛtɪk/adjective 2noun 2forms 1 adjective2 •Artificial, acting as a substitute for part of the body; relating to prosthesis. •Prothetic. noun2 •An artificial replacement for part of the body; a prosthesis, prosthetic device. •An addition to an actor etc.'s body as part of a costume, intended to transform the person's appearance. formsprosthetics