The name Clones is an anglicisation, of the Irish name Cluin Eois. The earliest form of the name is Cluain Auis. Cluain may mean a medow or as some authorities believe a height arising out of lowland or marsh.
Nobody can definitely say what Eois means, although many scholars believe that the word could refer to some topographical feature, such as a point or a tip. Cluain Eois therefore probably means the pointed hill arising out of a marsh. It has been said in tradition that Clones was an island. This most likely meant an island in a marsh, and in Winter it was almost surrounded by water. Even as late as 1606 Sir John Davies comments on roads from Clones "were nigh impassable due to bogs". The point or tip no doubt refers to the hill above the Diamond, the distinctive geographical feature, and the highest hill in the neighbour hood. In an effort to explain the meaning of the name early historians attempted an explanation, and the Dindseanchas of the I2th. century tells that Eois was the name of Conor Mac Nessa's swineherd.
Basin of The Erne River
Pre-Christian Clones was a place of little importance, and there are no references to it in the Ruraíocht or early stories. The Clones area is in the basin of the Erne river and it was probably inhabited at an early date. These early settlers used the Erne and the Finn rivers as waterways for transport, .and there are evidences of early burial sites at Wattlebridge, Carnmore on Sliabh Beagh, Scotshouse, Killeevan and Aghabog. The settlement in Clones was no doubt around the fort on the hill. It is difficult to say whether this was a ring fort used as an ordinary place of residence, or a hill fort used for defence. It is likely that the fort was the dwelling place of a local chieftain or the residence of a prosperous farmer.
The fort was enclosed by a rath or a rampart which contained the dwelling houses and farm buildings. The ordinary people lived in undefended house clusters in the vicinity Around the rath was arable land, and beyond was bog, moorland, rough pasture or woodland. It is likely that the house clusters and arable land stretched between the fort and Carra Street, and Mac Curtain Street. This was the longest and most gradual slope, and was ar aghaidh na graine agus ar chúl na gaoithe. When Tiarnach came to Clones therefore he was coming to establish a monastery in an area where people had already settled down.
Keating in his History of Ireland quoting an early source, makes a reference to Clones when he is giving an account of the borders of the kingdom of Neath. He says that this kingdom cave as far north as Cumar Chluana hEois. The name Cumar is still retained in the name Cumber Bridge, some two miles from Clones, and in the townland naves of Cloncumber and Kilcumber. Folklore tradition states that the fair of llones used be held at Cumber Bridge, and the site of the fair was known as Ballagh Ceister, and a village existed there. It had at least two inns and was later a favourite meeting place for cockfighters. The name of the village is probably still retained in the name, Pasture Gap, the name of a crossroads beside Cumber Bridge. There would appear to have been a recognised route or roadway between Ulster and Connacht passing by Cumber Bridge and Clones. In the Rura~ochr saga when Queen Meabh was attacking Eoghan Mac Dburthachta, king of Fearnmhaigh, who had his headquarters at Loch Uaithne, she must have come this way. They fought a battle at Cappagh, Cath Ceapaighe, near Smithboro. While the story may be legend the memory of a roadway remains. When Muircertach Ua Lochlainn, king of Aileach, was on his way to attack Connacht in 1161, the way they went (was) past the confluence of Cluain Eois - comar Cluana Eois. So Cumber was a well known place.