Mac Covey - Irish / Mheic Cobhthaigh. A Sept / Family branch, who had their territory in Co. Co. Down in the south - east of the Ulster Province, and nearby in Co. Louth in the north - east of Northern Leinster. Coffey also used as a derivation.

Cowan - Irish / Ua Comhdhain. A Sept / Family branch, who had their territory in Co. Kilkenny in the south - west of Southern Leinster, and nearby in Co. Waterford in the south - west of Ormond / Aur Mhumhain / Eastern Munster.

Cowan / Cobhainn. They were in Co. Offaly in the north - west of Southern Leinster.

Mac Cowhill or Mac Cowell. Used to anglicize Mac Cawell, which see, Irish / Mheic Cathmhaoil.

Mac Cowley. A Heremonian Ui Cobhthaigh Dal Cuinn Colla da Crioch Siol Daim Argait (Ui Cremthainn) Clann Lugainn Sept / Family branch. Especially see - Mac Anally.

Cowley. English toponymic origins. One of the "10 Foreign Tribes of Co. Kilkenny" in the south - west of Southern Leinster.

Mac Cowley A Heremonian Ui Cobhthaigh Dal Cuinn 3 Colla Sept / Family branch. Ancestors - *84.Eochy / Echu "Doimhlen," *83.Cairbre "Liffeachair" the 116th King of Tara / Ireland.  Also used as a variant for Mac Auley, which see, in Northern Connacht  and nearby in Co. Donegal in the north - west of the Ulster Province, and used in the Isle of Man without the Mac.

Mac Cowman - Irish / Mheic Comain. Used as a synonym with Commons and Cummins, which see, in Co. Wexford in the south - east of Southern Leinster where they had their original territory.

Cowman. Quaker origins. They were in Co. Dublin in the north - east of Southern Leinster in 1741 AD.

Mac Coy - Irish / Mheic Aodha. A Sept / Family branch, who had their territory in Co. Limerick in the mid - north - west of Thomond / Tuaiscert Mhumhain / Northern Munster.

Mac Coy. Highland Scottish origins. Gaelic Irish / Mheic Aodha. They were a galloglass / mercenary family who were in the Ulster Province.

Mac / O Coyle - Irish / Mheic Giolla Comhghaill. (Descended from a son of a devotee of St. Comhghall) A Sept / Family branch, who had their territory in Co. Donegal and Co. Monaghan in the west of the Ulster Province, and were also nearby in Co. Cavan in Southern Ulster. Also previously anglicized as Mac Ilhoyle, which see. See also Woods, and also often confused with Mac Cool.

O Coyne - Irish / Ua Cadhain - cadhan / wild goose. A Heremonian Ui Cobhthaigh Dal Cuinn Ui Fiachrach Sept / Family branch, who had their territory in Co. Mayo in the mid - west of the Connacht Province. Also used for Kyne or Coen, which see. See also Barnacle, Cowan and Kilcoyne. Ancestors - *87.Fiachra the original 2nd King of Connacht  (Ui Fiachrach), *86. Eochy "Mugmedon" the 124th King of Tara / Ireland.

Mac Cracken. Gaelic Irish / Mheic Reachtain. Used in Co. Antrim and Co. Derry in the  north - east of the Ulster Province for Mac Naughton.

Craddock / Creadoc. Welsh - caradoc. They were in the Co. Meath in the south - east of Northern Leinster, and Co. Kildare and Co. Kilkenny  in the south - west of Southern Leinster where there are Craddock towns.

Crahan. Used for Mac Crohan, which see, in Co. Kerry in south - west of Desmond / Southern Munster, for O Creaghan, which see, in Co. Mayo  in the mid - west of the Connacht Province, and changed to Craan and Curran in the Leinster Province.

Craig / sheer rock. Scottish origins. They were in Co. Antrim, Co. Derry and Co. Tyrone in the Ulster Province, and came after the early 17th Century AD Confiscation of the 3,500,000 acres of the Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill territories there, and the Foreign non - Catholic Plantations there.

Crampton. They have been in Co. Dublin in the north - east of Southern Leinster since the early 18th Century AD and prior.