Crug, a hillock. Pl. crugion.
Cwm, a valley, dingle, glen.
Cymmer, the junction of two rivers.
Dau, two.
Dehau, south, the right side.
Din, dinas, a city, a fort, a fortified place on a hill.
Dôl, a meadow.
Drws, a doorway.
Du, black; hence dwrdu, the river Dee; literally, Black-water.
Dwy, two. (fem.)