Master; sir; -- a Turkish title of respect, applied esp. to a state official or man of learning, as one learned in the law, but often simply as the courtesy title of a gentleman.

sir, as Hassan Effendi

A man of property, authority, or education in an eastern Mediterranean country (Turkish efendi master)

a former Turkish term of respect; especially for government officials

master; a term of respect

Title applied to persons of scholastic or official rank. Also a term of courtesy among equals.