Rhaiadr, a cataract, a waterfall.

Rhiw, a slope.

Rhôs, a moor.

Rhudd, crimson, ruddy.

Rhyd, a ford. Rhydycroesau, the ford of the Crosses.

Sarn, a causeway.

Serth, steep, abrupt.

Swydd, an office, a county.

Tal, the head or front. Talcen, the forehead.

Tan, under.