Cinn Tire: a place in Ulster
Clann Dedad: one of the three warrior-clans of Erin: a sept occupying the territory around Castleisland, County Kerry
Clann Rudraige: the warriors of King Conchobar: one of the three heroic tribes of Ireland
Clartha: Clara, near the present town of Mullingar, in the County Westmeath
Cletech: a residence of the kings of Ireland in Mag Breg, near Stackallan Bridge, on the banks of the Boyne
Clidna: see sub Tonn
Clithar Bo Ulad: probably in the centre of the County Louth
Cliu: an extensive territory in the county Limerick
Clothru: sister of Medb: Medb slew her while her son, Firbaide, was still unborn
Cluain Cain: now Clonkeen, in the west of County Louth