De Glin
de GLIN—XI—de Glyne, de Glen, Glynn, Glinn, Glenn; Norman 'de Glyn,' 'del Glyn,' i.e., of Glyn, a parish in Brecknockshire, or of the glyn, or glen. Glyn enters largely into the formation of Welsh place-names. The surname came into Ireland at an early period, but has always been very rare.
Alphabetical Index to Irish Surnames