Mac Girr - Irish / Mheic an Ghirr - gearr originally giorr. A Sept / Family branch, who had their territory in Co. Armagh in the south - east of the Ulster Province and were also in Co. Tyrone in Central Southern Ulster where some are known as Short. Mac Geer is also a variant used in Northern Leinster.

Girvan. Scottish origins. They were in Co. Antrim in the north - east of the Ulster Province.

Mac Given or Mac Giveen - Irish / Mag Dhuibhin or Mag Dhuibhfinn. See also Giffen. A Sept / Family branch, who had their territory in Co. Donegal in the north - west of the Ulster Province. Mac Kevin and Mac Avin - Irish / Mheic Dhuibhin variants are also used in Co. Donegal and nearby in Co. Sligo in the north - west of the Connacht Province.

Mac Giver or Mac Keever or Mac Kever or Mac Ever or Mac Ivor  / Mheic Iomhar, A Heremonian Ui Cobhthaigh Dal Cuinn Colla da Crioch Siol Daim Argait - (Ui Cremthainn) Clann Nadsluaigh Sept / Family branch - who had their territory at Clones in Co. Monaghan in Southern Ulster and nearby in Co. Louth in the north - east of Northern Leinster. Kinsmen to the Mac Mahons / Mac Mahan / Mac Maghan / Mheic Mathghamhna, Mac Ardle / Mac Ardall / Mac  Cardle / Mac Cardwell / Mheic Artghail, Mac Brady / Mheic Bradaigh, O Carroll / O Carool / Ui Cearbhaill, Mac Philip / Mac Phillips / Mac Phillip / Philipson. Ancestors - *92.Nadsluaigh, *91.Cairpre "Dam Argait," *90.Eochu, *89.Criffan / Crimthann "Lethan," *88.Fiacc, *87.Daig "Duirn," *86.Rochaid / Rochadh / Rochatha, *85.Murray / Muiredach Colla "da Crioch / Fo Crith" - of the Two Countries, *84.Eochy / Echu "Doimhlen," *83.Cairbre "Liffeachair" the 116th King of Tara / Ireland.

Mac Givern - Irish / Mag Uidhrin - odhar / dun coloured. A Sept / Family branch, who had their territory in Co. Armagh and Co. Down in the south - east of the Ulster Province. Bickerstaff, Biggar and Montgomery were also used as synonyms for Mac Givern in Co. Down.

Mac Givney - Irish / Mheic Dhuibhne. For a derivation see Deeney. A Sept / Family branch, who had their territory in the eastern part of the Diocese of Kilmore in Co. Cavan in Southern Ulster. The variants Mac Avinna, Mac Avinue and Mac Evinney where also used there.

O Glacken - Irish / Ua Glacain. A Sept / Family branch, who had their territory in Co. Donegal in the north - west of the Ulster Province and the surrounding regions.

Mac / O Gladdery - Irish / Mheic / Ua Gleadra. A Sept / Family branch, who were in the territory of the Heremonian Ui Cobhthaigh Dal Cuinn Ui Maine in Southern Connacht. In the Mid - 17th Century AD they were in Co. Tyrone in Central Southern Ulster and the surrounding region where O instead of Mac was also used.

Mac Glade. Gaelic / Mag Leid. Used as a variant for the Highland Scottish Mac Leod.

Mac Glade. Used as an abbreviation for Mac Gladdery, which see.

Mac Glancy or Mac Glancy. Used as a variant for Mac Clancy, which see, in the Heremonian Ui Cobhthaigh Dal Cuinn Ui Briuin kingdom of Breifne in Co. Leitrim in Northern Connacht. Ancestors - *87.Brion the original 1st King of Connacht (Ui Briuin), *86.Eochy "Mugmedon" the 124th King of Tara / Ireland.

Glanny or Glenny - Irish locative surname an Ghleanna (of the Glen).

Glanville or Glanfield. Anglo Norman origins. They have been in Ireland since the 14th Century AD in Southern Munster.

Glascoe. See - Glasscock.

Mac Glasgow. They were in Co. Tyrone and other parts of the Ulster Province where it was used as a variant for Mac Closkey, which see.

Mac Glashan. Usually Mheic Glasain / Mheic Glaisin - glas / green or grey green. They were in Co. Derry in the north - east of the Ulster Province where it was also changed to Green. See Mac Glashen and Glasier.

Glass - glas / green. They were in Co. Antrim and Co Derry in the north - east of the Ulster Province.

Glasscock. English toponymic origins. They were in Co. Kildare in Central Southern Leinster. Glascoe is a synonym used for Glasscock not Glasgow.

Mac Glaughlin. Used as a variant for Mac Gloughlin which see, in the Ulster Province.

O Glavin - Irish / Ua Glaimhin - glaimhin - glam / satirist. A Heremonian Ui Cobhthaigh Dal Cuinn Ui Fiachrach Sept / Family branch, who had their territory in the Connacht Province who are now also found in Co. Cork and Co. Kerry in Desmond / Southern Munster. Ancestors - *87.Fiachra the original 2nd King of Connacht (Ui Fiachrach), *86.Eochy "Mugmedon" the 124th King of Tara / Ireland.

Mac Glavin - Irish / Mag Laimhin previously Mag Fhlaithimhin - flaitheamh / ruler. A Sept / Family branch,- who had their territory in the Ulster Province. Also known as Hand by translation from lamh / hand. Not connected to O Glavin, but see also - Glavy.

Mac Glavy or Mac Glave - Irish / Mag Fhlaithimh. Later on Mag Laithimh was used. For a derivation see Mac Glavin. A Sept / Family branch, who had their territory in the Connacht Province, and it was also often changed to Hand in the belief it was derived from lamh / hand.