ma'am
/mæm/noun
1- a term of respectful or polite address used for女士; 夫人, 太太; 小姐：
1.1
- Brit. female royalty〈英〉对王室女性的尊称。
1.2
- a female police officer above the rank of sergeant who is senior to the speaker长官（对中士以上高于讲话人的女警官的称呼）。
1.3
- a female officer in the armed forces who is senior to the speaker长官（对高于讲话人的女军官的称呼）。
1.4
- N. Amer. or Brit. archaic any woman〈北美或英、古〉女士; 夫人, 太太; 小姐。
词源
mid 17th cent.: contraction of MADAM.