n.
Pronunciation: ' s ə r
Function: noun
Etymology: Middle English, from sire
Date: 13th century
1 a : a man entitled to be addressed as sir ― used as a title before the given name of a knight or baronet and formerly sometimes before the given name of a priest b : a man of rank or position
2 a ― used as a usually respectful form of address b capitalized ― used as a conventional form of address in the salutation of a letter