Mainly North American: transferred use of the surname, in origin a local name from any of various places in England named with the Middle English phrase atten whiten ey ‘by the white island’. In the 1980s its popularity as a girl's name was enhanced by the fame of the American singer Whitney Houston (b. 1963).
Southern English: topographic name for someone who lived in an area of downland (the rolling chalk hills of Sussex, Surrey, and Kent), from Old English dūn ‘down’, ‘low hill’ (of Celtic origin) + the suffix -er, denoting an inhabitant. Dun is a common element of English place names.