Modern Welsh coinage, composed of the vocabulary words glân ‘clean, pure, holy’ + da ‘good’. It is also used outside Wales, and is associated particularly with the actress and politician Glenda Jackson (b. 1937).
Scottish: habitational name from a place in Huntingdonshire (now part of Cambridgeshire), so called from Old English hramsa ‘wild garlic’ + ēg ‘island’, ‘low-lying land’. There are other places in England called Ramsey, but the one in Huntingdonshire is almost certainly the source of the surname. The usual spelling of the surname in Scotland is Ramsay.