Having or showing a capacity for protracted effort, regardless of difficulty or frustration
One thing that impresses everybody is Helen's tireless activity.
Aaron took quick steps, the way Alex did, and Rob had a tireless power walk.
It was nothing but excitement from first to last--drives, luncheons, receptions, and all that they involve when you have an eager, tireless child like Helen on your hands.
In Congress he proved to be a tireless advocate of the claims of the poorer whites and an opponent of the aristocracy.
To the upbuilding of this church Asbury gave the rest of his life, working with tireless devotion and wonderful energy.