OIr. word for (a) youth of an age to bear arms, (b) servant, messenger, gilly. Initially used with an epithet to describe servants, e.g. Gilla Decair [the Hard Servant] in Tóraigheacht an Ghiolla Dheacair [Pursuit of the Hard Gilly / Difficult Servant]. From the 10th century on, Gilla became the first element in masculine proper names, e.g. Gilla Cóemáin (fl.1025–75), the poet and chronicler, or the many-named Gilla Críst [Servant of Christ]. ModIr. giolla; ScG gille.