21-letter words containing a, b, u, l
- transcendental number — a number that is not a root of any algebraic equation having integral coefficients, as π or e .
- tubercular meningitis — an infection of the membranes of the central nervous system caused by the bacterium Mycobacterium tuberculosis; features can include fever, headache, and coma
- undesirable discharge — a discharge under other than honorable conditions of a person from military service by administrative action.
- 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.
- 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.
- william of malmesbury — William of, William of Malmesbury.
- yellow-rumped warbler — a common North American wood warbler, Dendroica coronata, having yellow spots on the rump, crown, and sides, including a white-throated eastern subspecies (myrtle warbler) and a yellow-throated western subspecies (Audubon's warbler)