In the nineteenth century, milord (also milor) (French pronunciation [milɔʁ]) was well known as a word that continental Europeans (especially French), whose jobs often brought them into contact with travellers (innkeepers, guides, etc.), commonly used to address Englishmen or male English-speakers who seemed to be upper-class (or whom they wished to flatter) – even though the English-language phrase "my Lord" (the source of "milord") played a somewhat minor role in the British system of honorific forms of address, and most of those addressed as "milord" were not in fact proper "lords" (members of the nobility) at all. The word "milord" was occasionally borrowed back into the English language in order to be used as a sarcastic or jocular reference to British travellers abroad.
(Most English-speaking tourists in the 18th century had to be rich to undertake the "Grand Tour".)
The most famous usage in recent years has been the 1959 French song "Milord" by Edith Piaf.
In Greece the equivalent was O Lordos; Lord Byron was known as "O Lordos" (The Lord), or "Lordos Veeron" (as the Greeks pronounce it), causing things as varied as hotels, ships, cricket teams, roads and even suburbs to be called "Lord Byron" today.
"Milord" (in this use generally pronounced as, and sometimes written as, "M'lud": /məˈlʌd/) is commonly perceived to be used by English barristers (lawyers who appeared in court), accused, and witnesses when addressing the judge adjudicating in the trial.
It is common to see in television or film portrayals of British courtrooms barristers addressing the judge as M'lud. This was the usual pronunciation until about the middle of the twentieth century in Courts in which the Judge was entitled to be addressed as "My Lord". However, it is a pronunciation which is now obsolete and no longer heard in Court. The modern pronunciation is "My Lord".
The correct term of address for a judge depends on his appointment. Judges of the High Court and of the Court of Appeal, and certain other Judges (notably, Honorary Recorders and Judges of the Old Bailey) are addressed as My Lord or My Lady.