adj.不知疲倦的；不懈的；不屈不撓的

Satisfaction of customers is just our untiring pursuit! 顧客的滿意是我們不懈的追求！

Strive for further development with untiring efforts. 以不懈的努力追求更廣闊的發(fā)展。

He appeared before me, not as the untiring and incomparable socialist agitator, but as a man of learning. 在我面前出現(xiàn)的他，并不是一位不屈不撓的和無與倫比的社會主義鼓動家，而是一位學(xué)者。