The name Merlin ranked 725th in popularity for males of all ages in a sample of the 1990 US Census.
Though this name appears on the 1990 U.S. Census lists, it is used by only a small percentage of the general population.
The modern names that derive from Myrddin are very controversial, and some authorities insist they were created by mistake.
In British legend, the wizard who tutored King Arthur was known as Myrddin Emrys. Writers translated this into Latin as Merlin Ambrosius, and into English as Mervyn, possibly in reference to the Welsh name Merfyn. Their mistake was believing that the first part of the name (Myrddin) was personal. It was, in fact, a place name -- the Welsh name for the seacoast town of Carmarthen. Emrys was the personal name -- a Welsh version of Ambrose.
So ''Ambrose of Carmarthen'' is possibly the best interpretation of the legendary Merlin's name. If it seems an insufficiently formidable name for a wizard, consider the meaning of Ambrose -- ''immortal.''