n. (pl. prostheses) 1 a an artificial part supplied to remedy a deficiency, e.g. a false breast, leg, tooth, etc. b the branch of surgery supplying and fitting prostheses. 2 Gram. the addition of a letter or syllable at the beginning of a word, e.g. be- in beloved. prosthetic adj. prosthetically adv.
[ LL f. Gk prosthesis f. prostithemi (as PROS-, tithemi place) ]