mod.nos.: mainly in Clare. Ir. Ó Cathaoir, from an old personal name thought to pre-date Celtic Ireland. Not connected with cathaoir meaning chair, which is a borrow-word from Latin cathedra. A popular name amongst the Ulstermen. SI.
Cahir: líon beag: an Clár & rl. Ainm pearsanta sa mheán-aois, Cathaoir.