Meaning

noun British marshal of the RAF who commanded the British air defense forces that defeated the Luftwaffe during the Battle of Britain (1882-1970)

noun deep-dish apple dessert covered with a rich crust

adjective lacking in smartness or taste

originFirst appears c. 1581. Origin uncertain, probably literally "little poorly dressed woman," formed from doue, "poorly dressed woman". Possibly also related to the Scots dow, meaning to "fade".

Etymology from Wiktionary, CC BY-SA 3.0