'Unflagging' definitions:

Definition of 'unflagging'

(from WordNet)
adjective
Showing sustained enthusiastic action with unflagging vitality; "an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence" [syn: indefatigable, tireless, unflagging, unwearying]
adjective
Unceasing; "unfailing loyalty"; "unfailing good spirits"; "unflagging courtesy" [syn: unfailing, unflagging]

Definition of 'Unflagging'

From: GCIDE