Save Type Surname (from occupation) Usage Irish Meaning & HistoryExpand Links Anglicized form of Mac Giolla Eoin. The last part of the surname was mistakenly taken as the Gaelic word for "Monday", Luain. Related NamesDetails Rootsgilla + EoinOther Languages & CulturesMacLean, McClain, McLain, McLean(Scottish) MacGillEain(Scottish Gaelic) Same SpellingMonday 1, Monday 2 Categories anglicizations