Pronunciation: (pros-thē'sis for 1; pros'thu-sis for 2), [key]
—pl. -sesPronunciation: (-sēz for 1; -sēz" for 2). [key]
1. a device, either external or implanted, that substitutes for or supplements a missing or defective part of the body.
2. Gram., Prosody.the addition of one or more sounds or syllables to a word or line of verse, esp. at the beginning.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.