Douglas. From its situation at the juncture of the two streams, the Dhoo, black, and Glass, grey.

Douro. From the Celtic Dwr, water.

Dover House. The residence of the Hon. George Agar Ellis, afterwards Lord Dover.

Dover Street. After Henry Jermyn, Lord Dover, who died at his residence here in 1782.

Dowager. The widow of a person of high rank, because she enjoyed a substantial dower or dowry for her maintenance during life.

Dowgate. From the Celtic Dwr, water. Hence a water gate on the north bank of the Thames.

Downing Street. From the mansion of Sir George Downing, M.P., of the Restoration period.

Down with the Dust. A gold miner’s expression in the Far West, where money is scarce and necessary commodities are in general bartered for with gold dust.

Doyley. From the Brothers Doyley, linen drapers in the Strand, who introduced this species of table napery.

Do your Level Best. This expression means that, while striving to the utmost you must also act strictly straightforward.