Mac Coitir
Mac COITIR—V—M'Cottir, MacCotter, MacCottier, MacCottar, Cotter, Cottier, Cottiers; 'son of Oitir' (the Norse Ottar); a variant of Mac Oitir (which see) by the attraction over of the c of Mac to the second part of the surname.
Alphabetical Index to Irish Surnames