Pronunciation: (fāth'lis), [key]
1. not adhering to allegiance, promises, vows, or duty: the faithless behavior of Benedict Arnold.
2. not trustworthy; unreliable.
3. without trust or belief.
4. being without religious faith.
5. (among Christians) bereft of Christian faith.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.