untiring

adj

1. Not able to be tired; inexhaustible.

   “It was the time of low Nile when all the land is baked like a crust of bread, when the creaking of the shadoofs and the singing croak of the sakkia are heard the night long like untiring crickets with throats of frogs.”

2. Unfailing; resolute.

   “A generation ago Chien-ch'ang was perhaps the least known part of all China to the outside world. About the middle of the thirteenth century the Mongol, Kublai Khan, acting as general of the forces of his brother, Genghis Khan, went through here to the conquest of Tali, then an independent kingdom in the southwest, and the untiring Venetian following in his train noted a few of the characteristics of Caindu, the name he gave both to the valley and the capital city.”

verb

1. (form-of, gerund, participle, present)present participle and gerund of untire