sirs

英 [sɜːz]

美 [sɜrz]

n. (对不认识的男性的尊称)先生; (正式信函中对不知其名的男性收信人的称呼)先生，阁下; (贵族头衔，用于爵士或准男爵的名字或姓名前面)爵士
sir的复数

柯林斯词典

N-VOC (对不知其姓名的男士或上级的尊称)先生，长官
People sometimes saysiras a very formal and polite way of addressing a man whose name they do not know or a man of superior rank. For example, a shop assistant might address a male customer assir.
1. Excuse me sir, but would you mind telling me what sort of car that is?...
  先生，请您告诉我那是什么类型的车好吗？
2. Good afternoon to you, sir.
  下午好，先生。
N-TITLE (用于爵士或准男爵的姓名前)爵士
Siris the title used in front of the name of a knight or baronet.
1. She introduced me to Sir Tobias and Lady Clarke.
  她把我引见给了托拜厄斯爵士和克拉克夫人。
CONVENTION (正式信函或商务信函开头的称呼语)先生，阁下(写信给某组织时使用 Dear sirs)
You use the expressionDear sirat the beginning of a formal letter or a business letter when you are writing to a man. You useDear sirswhen you are writing to an organization.
1. Dear Sir, Your letter of the 9th October has been referred to us.
  尊敬的先生，您 10 月 9 日的来信已转交我处。