21-letter words containing o, n, e, u
- up close and personal — face to face, intimately
- up hill and down dale — strenuously and persistently
- vasco nunez de balboa — Vasco Núñez de [bahs-kaw noo-nyeth th e] /ˈbɑs kɔ ˈnu nyɛθ ðɛ/ (Show IPA), 1475?–1517, Spanish adventurer and explorer who discovered the Pacific Ocean in 1513.
- ventriloquist's dummy — a puppet which is operated by a ventriloquist and made to appear to talk
- venus's flower basket — a glass sponge of the genus Euplectella, inhabiting deep waters off the Philippines and Japan, having a cylindrical skeleton formed of an intricate latticework of siliceous spicules.
- venus's looking glass — a purple-flowered campanulaceous plant, Legousia hybrida, of Europe, W Asia, and N Africa
- volumetric efficiency — the ratio of fluid delivered by a piston or ram pump per stroke to the displacement volume of the piston or ram
- voluntary arrangement — a procedure enabling an insolvent company to come to an arrangement with its creditors and resolve its financial problems, often in compliance with a court order
- volunteers of america — a religious reform and relief organization, similar to the Salvation Army, founded in New York City in 1896 by Ballington Booth, son of William Booth, the founder of the Salvation Army. Abbreviation: VOA.
- water of constitution — water present in a molecule that cannot be removed without disrupting the molecule.
- west lothian question — the apparent inconsistency that members of parliament who represent Scottish constituencies are eligible to vote at Westminster on matters that relate only to England, whereas members of parliament from English constituencies are not eligible to vote on Scottish matters
- whip-and-tongue graft — a graft prepared by cutting both the scion and the stock in a sloping direction and inserting a tongue in the scion into a slit in the stock.
- william the conqueror — ("the Conqueror") 1027–87, duke of Normandy 1035–87; king of England 1066–87 (son of Robert I, duke of Normandy).
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds