approval If you describe something such as support, effort, or enthusiasm as unflagging, you mean that it does not stop or get less as time passes. He was sustained by the unflagging support of his family The book is not one word too long and its narrative pace is unflagging. continuing strongly and never becoming tired or weak
showing sustained enthusiastic action with unflagging vitality; "an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence"