A male name. Gaelic, compound of donn ‘brown’, ceann ‘head’; the name of two early Scottish kings, Duncan I 1034-40, Duncan II 1094-5. It has always been a fairly common name in Scotland, but has not been adopted in England as other Scottish names have been. Donecan occurs, however in Domesday Book as the name of a sub-tenant in Somerset.

Of Celtic origin, this Scottish ‘Christian’ represents either Donnachu, ‘brown chief,’ or, less probably, Donngal, ‘brown stranger.’ Like Donald, Duncan occurs in the medieval Icelandic saga of Burnt Njal; the gentle, saintly king of Scotland in Shakespeare’s Macbeth is the C11 Duncan I of Scotland. (Yonge.)

A Scottish surname. Some render it ‘powerful chieftain.’ It is rather the English form of Donncha, q. v.

A Celtic name, meaning: Dark chief. (Teutonic) The people’s castle.

A Gaelic name: Donnchadh (Dial. Donnach), Middle Gaelic Duncha, Donnchaid, gen. (1467 MS.), Old Gaelic Donchad, Early Irish Donnchad: *Donno-catu-s, *Dunno-catu-s, “Brown warrior,” from donn and cath, q.v. The Gaulish Donno- of personal names has been referred by De Jubainville to the same meaning and origin as Middle Irish donn, king, judge, noble— a word occurring in O’Davoren’s glossary.