pleasantry       
noun [ C usually plural ]  formal uk/ˈplez.ən.tri/ us/ˈplez.ən.tri/
 客套话;打趣的话
a polite and often slightly humorous remark, usually made to help other people feel relaxed
  After exchanging pleasantries, the delegation revealed the purpose of their visit. 彼此寒暄一番之后,代表团说出了他们访问的目的。