tactfully       
adverb uk/ˈtækt.fəl.i/ us/ˈtækt.fəl.i/
 委婉地,圆通地
in a way that avoids saying or doing anything that could upset someone
  I tried to say as tactfully as I could that she was totally wrong. 我试图尽可能委婉地告诉她她完全错了。 
 Several friends had tactfully mentioned that when I was ready to start dating, they knew some great men. 有几个朋友曾委婉地提到,如果我准备好开始约会,她们认识一些不错的男人。 
 See: tactful
 - More examples
 - One guide gives tips on etiquette, including the correct way to tell a colleague tactfully about his or her body odor.
 - What you must do now is confront your mother with the truth as tactfully and forcefully as possible.
 - "Nice to have met you," said Meredith tactfully and moved off.
 - She wondered how she could tactfully drop a few hints about leaving without inviting a tirade of displeasure from André.