13-letter words containing o, a, r
- arteriovenous — of, relating to, or affecting an artery and a vein
- arthroconidia — Plural form of arthroconidium.
- arthroscopies — Plural form of arthroscopy.
- articulations — Plural form of articulation.
- arundinaceous — resembling a reed
- aryepiglottic — pertaining to or connecting the arytenoid cartilage and the epiglottis.
- ascorbic acid — Ascorbic acid is another name for vitamin C.
- asexual spore — a spore that is the result of asexual reproduction
- aspergillosis — a rare fungal infection, esp of the mucous membranes or lungs, caused by various species of Aspergillus
- aspirationals — Plural form of aspirational.
- assassinators — Plural form of assassinator.
- assembly room — a room used as a public place of entertainment, usually dating from the eighteenth or nineteenth century
- assortatively — In an assortative way.
- assortativity — (mathematics) The extent to which nodes of a graph link to others of the same degree.
- assyriologist — A person who studies ancient Assyria.
- aster yellows — a dwarfing and yellowing of asters and various other plants, caused by a mycoplasma transmitted by a leafhopper.
- astereognosis — inability to recognize objects by touch
- asteroid belt — the concentrations of asteroids that move around the sun mainly between the orbits of Mars and Jupiter
- asthenosphere — a thin semifluid layer of the earth (100–200 km thick), below the outer rigid lithosphere, forming part of the mantle and thought to be able to flow vertically and horizontally, enabling sections of lithosphere to subside, rise, and undergo lateral movement
- astrodynamics — the study of the motion of natural and artificial bodies in space
- astronautical — of or relating to astronautics or astronauts.
- astroparticle — (astrophysics) A subatomic particle of cosmic origin.
- astrophysical — Of or pertaining to astrophysics.
- aten asteroid — one of a small group of asteroids whose orbits cross that of the earth and whose semimajor axes are smaller than that of the earth.
- athenagoras i — (Aristocles Spyrou) 1886–1972, Archbishop Ecumenical of Constantinople and Ecumenical Patriarch of the Greek Orthodox Church 1948–72.
- atherogenesis — (medicine) The formation of atheromas, especially on the walls of the arteries.
- atmospherical — pertaining to, existing in, or consisting of the atmosphere: atmospheric vapors.
- atomic energy — nuclear energy
- atomic number — the number of protons in the nucleus of an atom of an element
- atomic theory — any theory in which matter is regarded as consisting of atoms, esp that proposed by John Dalton postulating that elements are composed of atoms that can combine in definite proportions to form compounds
- atrabilarious — Characterized by melancholy or gloom.
- atroceruleous — a deep blue-black color.
- atrociousness — The state of being atrocious.
- attested form — a linguistic form that can be shown to be in use or in written records
- attributional — of or relating to the act of attributing
- auctioneering — Present participle of auctioneer.
- audience room — a room for holding formal interviews or hearings.
- audiographics — audiographic teleconferencing
- aum shinrikyo — a syncretistic Japanese cult combining elements of Buddhism, Hinduism, and Christianity, founded by Shoko Asahara in 1986; responsible for a number of murders and in particular a nerve-gas attack on the Tokyo underground in 1995
- austroasiatic — a family of languages spoken in SE Asia and the landsaround the Bay of Bengal and consisting principally of Vietnamese, Khmer, Mon, Khasi, Nicobarese, and the Munda languages.
- autapomorphic — (biology) Describing any characteristic that has evolved in only a single species (or other taxon).
- auteur theory — the theory that creative directors are the major force in film-making
- authenticator — a person or thing that authenticates.
- authorisation — Alternative spelling of authorization.
- authoritarian — If you describe a person or an organization as authoritarian, you are critical of them controlling everything rather than letting people decide things for themselves.
- authoritative — Someone or something that is authoritative gives an impression of power and importance and is likely to be obeyed.
- authorization — an authorizing or being authorized
- auto-destruct — self-destruct.
- auto-injector — An auto-injector is a hypodermic syringe that you can use to inject yourself with a liquid.
- autobiography — Your autobiography is an account of your life, which you write yourself.