Merlin is the Latinized form of the Welsh Myrddin, which is usually explained as "sea fortress" from the old name of the town of Carmarthen. Geoffrey of Monmouth coined the spelling in the 12th century for the wizard of the Arthurian legends, and the name also belongs to a small, fast falcon. In the United States Merlin has stayed in the 2000s and low 3000s since 2000, with a best rank of 1998 in 2001; it ranks number 2343 in 2025.