Bridgend and The Vale
Coedymwstwr is the name of a Golf Club and Hotel near Coychurch (coed & church), Bridgend. It was also previously the name of the farms Coedymwstwr Ganol, Uchaf and Isaf. Coed (woods, trees) is a common place-name element in the area, as witnessed in Pen-coed, Tor-coed, Coedypebyll and Coety (coed & ty).
The second element mwstwr is interesting. Popular etymology links it to Welsh mwstwr 'noise, bustle' giving Coedymwstwr a meaning of 'noisy woods' which may be implied by'Whispering Woods', the name given to the sixth hole of the golf course. However, Professor Emeritus G. O. Pierce (Place-Names in Glamorgan, 45-47) informs us that here, mwstwr is the spoken Welsh form of the old Welsh word mystwyr. This is derived from Vulgar Latin mon'sterium, originally monasterium which also gave English minster 'abbey church, cathedral'. One should not expect to find the remains of a large medieval priory here, but rather those of a small cell of the early Christian era, possibly linked to the nearby Llangrallo (church of Crallo) also called Coychurch.
Cae'r ffunnon (the well field) is an interesting field-name on Coedymwstwr Ganol reorded on a Dunraven Estate map of 1778. The well itself is named Funnon -y-Munalog (Ffynnon y fynachlog) 'the monastary well'.
NLW Journals online.