un·fail·ing 
/ˌʌnˈfeɪlɪŋ/ adjective
/ˌʌnˈfeɪlɪŋ/ adjective : not failing or likely to fail: such as a : never changing or becoming weaker even in difficult times
▪ unfailing loyalty/support ▪ She is known for her unfailing optimism.
b : always providing enough of what is needed
▪ an unfailing [=inexhaustible] supply
▪ unfailing loyalty/support ▪ She is known for her unfailing optimism.
b : always providing enough of what is needed
▪ an unfailing [=inexhaustible] supply
— un·fail·ing·ly adverb
▪ He is unfailingly [=always] punctual/polite.
▪ He is unfailingly [=always] punctual/polite.
