Adjective: unfailing ,ún'fey-ling
- Not liable to failure
"the unfailing sign of an amateur"; "an unfailing test";
- foolproof, idiot-proof [informal]
- Always able to supply more
"an unfailing source of good stories"; "a subject of unfailing interest"
- Tireless
"unfailing loyalty";
- unflagging
See also: constant, inexhaustible, infallible, unlimited