21-letter words containing m, a, c, 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
- tuple space smalltalk — ["Using Tuple Space Communication in Distributed Object-Oriented Languages", S. Matsuoka et al, SIGPLAN Notices 23(11):276-284 (Nov 1988)].
- 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-vascular system — a system of closed, fluid-filled tubes and ducts of echinoderms used in clinging, locomotion, feeding, and respiration.
- william the conqueror — ("the Conqueror") 1027–87, duke of Normandy 1035–87; king of England 1066–87 (son of Robert I, duke of Normandy).