sincerity

n. 诚实,真实,诚心诚意

I may say in all sincerity that you have been my most loyal friend.

我可以非常真诚地说，你一直是我最忠实的朋友。

Having a face that seems to exhibit honesty and sincerity.

相貌老实的，坦率的看起来相貌坦率诚实的