Cubbon

Cubbon is a rare patronymic manx gaelic (Gaelg) surname, of exclusive origin from the Isle of Man.
Origins and meaning.
Cubbon is one of the rare manx surnames, of either Irish Gaelic or Scottish Gaelic ancient origin. The surname Cubbon is a Manx contraction of the Irish surname ‘Mac Gibbon’ or the Scottish variant ‘MacGibbon’ meaning ‘son of Gilbeirt’. Gilbeirt itself meaning: ("pledge", "hostage", "noble youth") and ("bright", "famous") 
The Cubbon surname originally possessed the variations of the gaelic Mac prefixes (Mac/Mc or M’), which were universally used in surnames on the Isle of Man. By the 17th century the prefix had almost completely disappeared. When the Mac prefix fell out of use, the final consonant became the first sound of the surname. Because of this, many Manx names characteristically begin with the letters C, K, or Q.
Cubbon and its numerous variations are commonly associated in Ireland with the descendants of Gilbert Fitzgerald, a younger son of John Fitzgerald, ancestor of the houses of Kildare and Desmond. Or as variations of the sept name of the highland Scottish clan Buchanan, after the clan chief Gilbert Buchanan.
Variations.
As an old gaelic name that exist in the three branches of the Goidelic languages, Cubbon has/had numerous variations: M’Cubbon (1430), MacCubbon/ McCubbon/ MacCubbin/ McCubbin (1511), Cubbon (1605), Cubon (1649) and Cubbin (1645) 