gráinne is a feminine given name in the irish language. the name is of an uncertain origin, although it is possible that it may be connected with the word "ghrian", meaning "the sun". in irish legend, deorghrianne (a tear of the sun), is the daughter of fiachna, son of betach. the name is also borne by a famed character in irish mythology—gráinne, who was the daughter of cormac mac airt, a legendary high king of ireland.