prosthesis
noun (an artificial part of the body, for example a leg, an eye or a tooth 假体（如假肢、假眼或假牙） Word Originmid 16th cent. (originally denoting the addition of a letter or syllable at the beginning of a word): via late Latin from Greek prosthesis, from prostithenai, from pros ‘in addition’ + tithenai ‘to place’.