16-letter words starting with a
- antoinette perry — Antoinette, 1888–1946, U.S. actress, theatrical manager, and producer.
- anxiety disorder — any of various mental disorders characterized by extreme anxiety and including panic disorder, post-traumatic stress disorder, and generalized anxiety disorder
- anxiety neurosis — a relatively mild form of mental illness characterized by extreme distress and agitation, often occurring without any obvious cause
- apical dominance — suppression of the development of lateral buds in a growing plant shoot, caused by hormones produced in the tip of the shoot.
- aplastic anaemia — anaemia caused by a defect in the body's ability to regenerate blood cells
- apollo belvedere — a Roman marble statue, possibly a copy of a Greek original of the 4th–1st centuries b.c.
- apostolic church — the Christian church as founded by the apostles.
- apparent horizon — the apparent line that divides the earth and the sky
- appeals tribunal — a tribunal that hears appeals
- appearance money — Appearance money is money paid to a famous person such as a sports star or film star for taking part in a public event.
- apple of discord — a golden apple inscribed "For the fairest". It was claimed by Hera, Athena, and Aphrodite, to whom Paris awarded it, thus beginning a chain of events that led to the Trojan War
- apple tree borer — Also called flatheaded apple tree borer. the larva of a metallic wood-boring beetle, Chrysobothris femorata, that bores into the wood of apple and other fruit trees.
- apple-touch-icon — (programming) (apple-touch-icon.png) Apple's default icon (image) used to represent a website, e.g. when saved as a bookmark or on the home screen of an iOS device such as an iPhone or iPad. Apple's scheme allows a site to offer images of different sizes so the client can choose the most appropriate one according to its screen size and resolution. Apple devices and applications completely ignore the favicon.ico de facto standard which, while somewhat quirky in its use of the ico format, has been pretty much universally adopted elsewhere. Conversely, apple-touch-icon.png will be ignored by non-Apple devices, possibly because its 16x16 resolution would look pretty shabby on most smart phones.
- apples and pears — stairs
- appliance garage — a kitchen compartment or cabinet designed for housing frequently used small electric appliances.
- application form — a form to be filled in when applying for job, grant etc
- applied research — research that is put to practical use
- applied sciences — sciences that are put to practical use
- appraisal method — a method used for the appraisal of an employee
- appreciativeness — The state or quality of being appreciative.
- apprehensiveness — uneasy or fearful about something that might happen: apprehensive for the safety of the mountain climbers.
- approachableness — capable of being approached; accessible.
- april fool's day — April Fool's Day is the 1st of April, the day on which people traditionally play tricks on each other.
- april fools' day — April 1, a day when practical jokes or tricks are played on unsuspecting people.
- aquidneck island — an island in Narragansett Bay, Rhode Island.
- arachidonic acid — a fatty acid occurring in animal cells: the metabolic precursor of several groups of biologically active substances, including prostaglandins
- aratus of sicyon — 271–213 b.c, Greek general: leader of the Achaean League.
- archaeoastronomy — the scientific study of the beliefs and practices concerning astronomy that existed in ancient and prehistoric civilizations
- archaeologically — In an archaeological manner.
- archaeomagnetism — an archaeological technique for dating certain clay objects by measuring the extent to which they have been magnetized by the earth's magnetic field
- archconservative — consistently holding extremely conservative views: publisher of the city's archconservative newspaper.
- archival storage — a method of retaining information outside of the internal memory of a computer
- arctic red river — a river in the W Northwest Territories, Canada, flowing NW to the Mackenzie River. 310 miles (500 km) long.
- aristocratically — In an aristocratic manner.
- armchair banking — the management of one's bank account or accounts using a computer, telephone, or television in the home or via the postal system
- armed forces day — the third Saturday in May, observed in some areas of the U.S. as a holiday in honor of all branches of the armed forces.
- armed neutrality — military preparedness without commitment, especially as the expressed policy of a neutral nation in wartime; readiness to counter with force an invasion of rights by any belligerent power.
- armillary sphere — a model of the celestial sphere consisting of rings representing the relative positions of the celestial equator, ecliptic, etc, used by early astronomers for determining the positions of stars
- arms and the man — a comedy (1898) by G. B. Shaw.
- aromatherapeutic — Of or pertaining to aromatherapy.
- around the clock — continuing without pause or interruption: an around-the-clock guard on the prisoner.
- around the world — in many countries
- around-the-clock — all day and all night
- arrival platform — the platform where a train, or passenger arrives
- ars gratia artis — art for art's sake
- arsenic trioxide — a white poisonous powder used in the manufacture of glass and as an insecticide, rat poison, and weedkiller. Formula: As2O3
- arteriocapillary — Relating to the arteries and the capillaries.
- arteriosclerosis — Arteriosclerosis is a medical condition in which the walls of your arteries become hard and thick, so your blood cannot flow through them properly.
- arteriosclerotic — degenerative changes in the arteries, characterized by thickening of the vessel walls and accumulation of calcium with consequent loss of elasticity and lessened blood flow.
- arthroscopically — By means of arthroscopy.