MacDonald,
Macdonald, and
McDonald are
Anglicised forms of the
Scottish Gaelic and Irish Gaelic name
MacDhòmhnaill, which in modern Gaelic is approximated as
McConnell. It is a
patronym where
Mac means "son" and
Dhòmhnaill means "of Dòmhnall". The personal name
Dòmhnall is composed of the elements
domno "world" and
val "might", "rule". According to
Alex Woolf, the Gaelic personal name is probably a borrowing from the
British Dyfnwal.