1. (Eastern Orthodox Church) a small side table or altar where the Eucharistic elements are prepared before the liturgy
   "The priest arranged the bread and wine on the prothesis before the service"
    
2. (linguistics) the addition of a sound or syllable at the beginning of a word
   "The Spanish word 'escuela' shows prothesis compared to the Latin 'schola'"

Derived forms: protheses

Encyclopedia: Prothesis