Webster’s Revised Unabridged Dictionary · 1913
Prosthesis
Pros′the·sis (prŏs′thē·sĭs), n. [L., fr. Gr. πρόσθεσις an addition, fr. προστιθέναι to put to, to add; πρός to + τιθέναι to put, place.] 1. (Surg.) The addition to the human body of some artificial part, to replace one that is wanting, as a log or an eye; — called also prothesis.
2. (Gram.) The prefixing of one or more letters to the beginning of a word, as in beloved.