Mac Griskin - Irish / Mheic Cristin? A Sept / Family branch, who had their territory in Co. Leitrim in Northern Connacht.

Mac Groake or Mac Grourke - Irish / Mag Ruairc. A Heremonian Ui Cobhthaigh Dal Cuinn "Southern" Ui Niaill Sept / Family branch, who are now in Co. Mayo in the mid - west of the Connacht Province. Ancestor - *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill).

Mac Groarty - Irish / Mag Robhartaigh. A Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill Cenel Conaill Sept / Family branch, who had their territory at Ballymagroarty in Co. Donegal in the north - west of the Ulster Province who were the Keepers of the Psalter of St. Columb Cille / St. Columba. See also Mac Roarty. Ancestors - *88.Conall "Gulban" the 1st King of Tir Conaill (Cenel Conaill), *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill).

Mac Groddy or Mac Grody or Mac Gruddy - Irish / Mag Rodaigh - rod / strong. An Erenagh Sept / Family branch of Desertegney, who had their territory at Inishowen in Co. Donegal in the north - west of the Ulster Province.  

Mac Groden or Mac Grudden - Irish / Mag Rodain. A Sept / Family branch, who had their territory in the Connacht Province. See also Rodden.

O Grogan or O Groogan - Irish / Ua Gruagain / Ua Ghrogain - gruag / hair / grug - fierceness.  A Sept / Family branch, who had their territory in Co. Roscommon in the east of the Connacht Province who are the most widely dispersed Sept in Ireland. O Grugan and O Groggan are used as variants in the Ulster Province. They were also in Co. Cork in Desmond / Southern Munster.

Mac Gronan. Used as a synonym for Reynolds, which see, in Co. Armagh in the south - east of the Ulster Province giving Mag Raghainn as a variant in Irish.

Mac Grotty - Irish / Mag Ratha. A Sept / Family branch, who had their territory in Co. Derry and nearby in Co. Tyrone in the Ulster Province.

Grove or Groves. English locative origin. They were in Co. Cork in Southern Munster in the 17th Century AD. See also Graves.

Mac Growder or Mac Grudder - Irish / Mag Bhruadair. From Broder a Norse personal name. They were in the Heremonian Ui Cobhthaigh Dal Cuinn 3 Colla kingdom of Orghialla / Airghialla / Oriel in Southern Ulster and nearby in Co. Louth in the north - east of Northern Leinster

O Growney. A corrupted form of Mheic Carrghamhna later also changed to Mac Carron / Mheic Gramhna. A Sept / Family branch, who had their territory in Co. Westmeath in the south - west of Northern Leinster and nearby in Co. Tipperary in the north - east of Thomond / Northern Munster.

Mac Guane - Irish / Mheic Dhubhain - dubh / black. A Sept / Family branch, who had their territory in Co. Donegal in the north - west of the Ulster Province where it was absorbed by Mac Gowan. Also known as Mac Guane in Co. Clare in Thomond / Northern Munster

O Gubbins or O Gobban - Irish / Ua Goibin / Ua Gobain - gob / mouth. A Sept / Family branch, who had their territory in Co. Donegal and nearby in Co. Derry in the north of Ulster Province.

Mac Guckin or Mac Guckian. A Sept / Family branch, who had their territory in Co. Leitrim in Northern Connacht. See also Mac Guigan and Hackett / Guckian.

Mac Guckin or Mac Guckian - Irish / Mag Eochaidhin. A Sept / Family branch, who had their territory in the Ulster Province.

O Guerin - Irish / Ua Gearain. A Sept / Family branch, who had their territory in Co. Mayo in the mid - west of the Connacht Province.

Guerin. A Sept / Family branch, who had their territory in Co. Limerick in the mid - west of the Munster Province and nearby in Co. Kerry in the south - west  in Iar Mhumhain / South Western Munster where they were known there as Geran and Gerin. Changed to Green in Athlone in Co. Westmeath in the south - west of Northern Leinster. It was also used as a synonym for Mac Givern, which see, in the Ulster Province.

Guerin. French Huguenot origins. They were in Co. Mayo in the mid - west of the Connacht Province.