unwearied

They are a mad, racing breed—fat, unwearied, and strenuous—the pick of their species.

The years from 1854 to 1860 were on his part years of constant, active, and unwearied effort.

By exception, one listener sat it out with unwearied attention.

I was struck with his holy devotedness to his great object, with his unwearied diligence, with his unbounded charity.