How do you call a male witch?

[Durkoala]

Just once, as a governmental title roughly equivalent to Chief Justice.

Rowling's notes of Dumbledore's notes in The Tales of Beedle the Bard say that 'Warlock' is equivelant to a knighthood, or 'Sir'. At some point in time (I can't remember if it applies at the time of the main series or not), it also meant 'argumentitive wizard'.