A very, very rare first name. It is a Welsh version of "John".
A quick survey of the people on ICQ indicates that only about 0.000035% of people have this as a first name (3.477 x 10-7). For comparison, 0.96% of people on ICQ have "John" as their first name.
A real pain to have this name, because to other people, it's hard to say. :)