Sirs vs. Sir — What's the Difference?

Sirs is a surname.

Sir is a formal English honourific address for men, derived from Sire in the High Middle Ages. Traditionally, as governed by law and custom, "Sir" is used for men titled as knights, i.e., of orders of chivalry, and later also applied to baronets and other offices.

Sir Used as an honorific before the given name or the full name of baronets and knights.

Sir Used as an honorific before the given name or the full name of baronets and knights.

Used as a form of polite address for a man

Used as a form of polite address for a man

Used as a salutation in a letter

Used as a salutation in a letter

Plural of sir

A man of a higher rank or position.

A respectful term of address to a man of higher rank or position, particularly:

To a knight or other low member of the peerage.

To a superior military officer.

To a teacher.

A respectful term of address to an adult male (often older), especially if his name or proper title is unknown.

To address (someone) using "sir".

A man of social authority and dignity; a lord; a master; a gentleman; - in this sense usually spelled sire.

A title prefixed to the Christian name of a knight or a baronet.

An English rendering of the LAtin Dominus, the academical title of a bachelor of arts; - formerly colloquially, and sometimes contemptuously, applied to the clergy.

A respectful title, used in addressing a man, without being prefixed to his name; - used especially in speaking to elders or superiors; sometimes, also, used in the way of emphatic formality.

Term of address for a man

A title used before the name of knight or baronet