Eu.

From BMEzine Encyclopedia

Eu is a title short for "eunuch."

It is of course common to refer to a man with the title "Mr." (short for mister), and a woman with the titles "Ms.", "Mrs.", or "Miss". The title "Eu." is used when referring to a Eunuch.

"Ten years ago we called him 'Mr. Jones',
but since the operation, we call him 'Eu. Jones'."

There is no known historical basis to this term.