Pronunciation: (yOO"thu-nā'zhu, -zhē-u, -zē-u), [key]
1. Also called mercy killing. the act of putting to death painlessly or allowing to die, as by withholding extreme medical measures, a person or animal suffering from an incurable, esp. a painful, disease or condition.
2. painless death.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.