nouna former county of SE Wales: divided into West Glamorgan, Mid Glamorgan, and South Glamorgan in 1974; since 1996 administered by the county of Swansea and the county boroughs of Neath Port Talbot, Bridgend, Rhondda Cynon Taff, Vale of Glamorgan, Merthyr Tydfil, and part of Caerphilly