in a way that shows that you are shy and not confident of your abilities

"Maybe you should leave us for a moment," the old man suggested diffidently. “或许你应该离开我们一会儿。”老人踌躇着提议道。

They came in diffidently, and nodded respectfully to Wilcox. 他们腼腆地走进来，恭敬地向威尔科克斯点点头。