Of the few native Briton, or Celtic, words that survive in modern English, most are related to
geography. They describe natural features that were probably new to later
invaders, such as--
crag (steep cliff or rock)
tor (high rock)
cumb (deep valley)
luh (lake)
Celtic also survives in modern place-names:
avon, dover, wye, exe, thames (names for water, which still name rivers in Britain)
bryn mawr (great hill)
London, Exeter, Salisbury, and names of other cities