Gilmore and Gillmore are surnames with several origins and meanings.
[2] Gilmore is an alternative, or sept, of Clan Morrison from Scotland, known as MacGilleMhoire in Scottish Gaelic.
Gillmore has been noted as a derivative of the Scottish Gaelic Gille-mohr, meaning "great servant", a name given to the armour-bearer to a Highland chief,[3]: 129 or more prosaically to the servant or henchman of a chief.
[3]: 416 Another origin of the surname Gilmore is Irish, with two separate meanings.
[2] In County Sligo, Gilmore is an Anglicisation of Mac Giolla Mhir meaning "son of the spirited lad".