15-letter words starting with a
- athlete's heart — enlargement of the heart, caused by continued, heavy physical exertion
- athletic sports — sports, esp track and field events, in which athleticism is required
- atlantic puffin — any of several alcidine sea birds of the genera Fratercula and Lunda, having a short neck and a large, compressed, grooved bill, as F. arctica (Atlantic puffin) of the North Atlantic.
- atlantic ridley — ridley (def 1).
- atlantic salmon — a valuable food and game fish, Salmo salar, mainly of northern coastal Atlantic waters or, when spawning, in freshwater streams tributary to the ocean.
- atlantic-ridley — ridley (def 1).
- atlas mountains — a mountain system of N Africa, between the Mediterranean and the Sahara. Highest peak: Mount Toubkal, 4165 m (13 664 ft)
- atmospherically — pertaining to, existing in, or consisting of the atmosphere: atmospheric vapors.
- atomic cocktail — an aqueous solution of radioactive substance administered orally as part of the treatment for cancer
- atrabiliousness — The state or quality of being characterized by melancholy or glumness.
- attitude survey — a survey of the opinions held by a particular group of people
- attorney-at-law — a lawyer qualified to represent in court a party to a legal action
- audience appeal — the quality of being attractive to an audience
- audience rating — a figure based on statistical sampling indicating what proportion of the total listening and viewing audience tune in to a specific programme or network
- audio equipment — electrical devices used to play or record sound
- audio frequency — a frequency in the range 20 hertz to 20 000 hertz. A sound wave of this frequency would be audible to the human ear
- audio recording — an electronic recording of sound
- auditor general — (in Canada) a federal official responsible for auditing government departments and making an annual report
- audubon society — a North American organization devoted to the conservancy of birds
- auf wiedersehen — goodbye, until we see each other again
- augmented roman — a writing system based on an expanded English alphabet, consisting of 43 characters representing different phonemes of spoken English, used for teaching beginners to read. Abbreviation: I.T.A., i.t.a.
- augmented sixth — an interval greater than a major sixth by a chromatic half step.
- augusta emerita — a market town in W Spain, in Extremadura, on the Guadiana River: founded in 25 bc; became the capital of Lusitania and one of the chief cities of Iberia. Pop: 52 110 (2003 est)
- augusta gregory — Lady Augusta (Isabella Augusta Persse) 1852–1932, Irish dramatist.
- augustus caesar — Also called Octavian (before 27 b.c.)(Gaius Julius Caesar Octavianus; Augustus Caesar) 63 b.c.–a.d. 14, first Roman emperor 27 b.c.–a.d. 14: reformer, patron of arts and literature; heir and successor to Julius Caesar.
- aurora borealis — the aurora seen around the North Pole
- australian alps — a mountain range in SE Australia, in E Victoria and SE New South Wales. Highest peak: Mount Kosciuszko, 2195 m (7316 ft)
- australian mist — a breed of medium-sized cat with a short spotted or marbled coat
- australian pine — casuarina
- austria-hungary — the Dual Monarchy established in 1867, consisting of what are now Austria, Hungary, the Czech Republic, Slovakia, Slovenia, Croatia, and Bosnia-Herzegovina, and parts of Poland, Romania, Ukraine, and Italy. The empire was broken up after World War I
- authenticatable — to establish as genuine.
- authentications — Plural form of authentication.
- authoritatively — having due authority; having the sanction or weight of authority: an authoritative opinion.
- autobiographers — Plural form of autobiographer.
- autobiographies — Plural form of autobiography.
- autocannibalism — The eating of part of one's own body.
- autocollimation — the process used in an autocollimator.
- autocorrelation — the condition occurring when successive items in a series are correlated so that their covariance is not zero and they are not independent
- autocorrelative — Relating to autocorrelation.
- autodestructive — likely to cause one's own destruction
- autodidacticism — any self-directed learning or self-education
- autofluorescent — Of, pertaining to, or exhibiting autofluorescence.
- autoinoculation — the inoculation of microorganisms (esp viruses) from one part of the body into another, usually in the form of a vaccine
- autolithography — a lithographic technique by which the artist draws or traces with a brush and pen directly on a stone or plate.
- automata theory — the formal study of the power of computation of abstract machines
- automatic drive — an automotive transmission requiring either very little or no manual shifting of gears.
- automatic focus — a system in a camera which automatically adjusts the lens so that the object being photographed is in focus, often one using infrared light to estimate the distance of the object from the camera
- automatic pilot — An automatic pilot or an autopilot is a device in an aircraft that automatically keeps it on a particular course.
- automatic rifle — a type of light machine gun capable of firing automatically or in single shots.
- automorphically — in an automorphic manner