This name was not regularly given to people until the 19th century [4][3]. It was used by George Eliot for a character in her novel Daniel Deronda (1876).
This name appears briefly in a poem in the Black Book of Carmarthen in the form Kyrridven [1] and in a poem in the Book of Taliesin in the form Kerrituen [2]. Some theories connect her to an otherwise unattested Celtic goddess of inspiration, and suppose her name is related to Welsh cerdd "poetry".