12-letter words containing r, o
- archaization — Process of becoming or turning something more archaic.
- archdeaconry — the office, rank, or duties of an archdeacon
- archdiocesan — Relating to an archdiocese.
- archdioceses — Plural form of archdiocese.
- archegoniate — having archegonia
- archenterons — Plural form of archenteron.
- archeologist — archaeology.
- archeopteryx — A specimen of the species Archaeopteryx lithographica, being the earliest and most primitive known bird, representing a transition in the evolution of dinosaurs to birds.
- archesporial — the primitive cell, or group of cells, that give rise to the cells from which spores are derived.
- archesporium — archespore.
- archibenthos — the ocean bottom between the littoral and abyssal zones: from depths of approximately 200 feet (60 meters) to 3300 feet (1000 meters).
- archilochian — denoting or relating to the 7th century bc Greek poet Archilochus or his verse, esp the iambic trimeters or trochaic tetrameters used by him
- archipelagos — Plural form of archipelago.
- archiphoneme — an abstract linguistic unit representing two or more phonemes when the distinction between these has been neutralized: conventionally shown by a capital letter within slashes, as /T/ for /t/ and /d/ in German Rat and Rad
- archosaurian — belonging to or characteristic of the archosaurs
- arctic ocean — the ocean surrounding the North Pole, north of the Arctic Circle. Area: about 14 100 000 sq km (5 440 000 sq miles)
- arctophilist — a collector of teddy bears
- area bombing — aerial bombing in which bombs are dropped over the general area of a target.
- arfvedsonite — a type of hornblende with the composition Na3(Fe,Mg)4FeSi8O22(OH)2
- argillaceous — (of sedimentary rocks and deposits) composed of very fine-grained material, such as clay, shale, etc
- aria da capo — an operatic aria in three sections with the first and third sections alike and the middle section contrasting.
- ariel sharon — Ariel, 1928–2014, Israeli military and political leader; prime minister 2001–06.
- aripiprazole — An antipsychotic drug used in the treatment of schizophrenia etc.
- aristocratic — Aristocratic means belonging to or typical of the aristocracy.
- aristolochia — any of various plants of the genus Aristolochia of the family Aristolochiaceae
- aristophanes — ?448–?380 bc, Greek comic dramatist, who satirized leading contemporary figures such as Socrates and Euripides. Eleven of his plays are extant, including The Clouds, The Frogs, The Birds, and Lysistrata
- aristophanic — 448?–385? b.c, Athenian comic dramatist.
- aristotelian — of or relating to Aristotle or his philosophy
- arithmomania — an obsessive desire to count objects, or a fixation with numbers and calculations
- armed forces — The armed forces or the armed services of a country are its military forces, usually the army, navy, marines, and air force.
- armor-plated — An armor-plated vehicle or building has a hard metal covering in order to protect it from gunfire and other missiles.
- armored rope — rope made of wire-wrapped hempen strands that is used in salvage work.
- armour plate — a tough heavy steel, usually containing chromium, nickel, and molybdenum and often hardened on the surface, used for protecting warships, tanks, etc
- armourbearer — One who carries armor for another.
- armoured car — a fast lightly armed and armoured vehicle, mainly used for reconnaissance
- arms control — an agreement between two or more countries to reduce the number of weapons owned, with the aim of preventing war
- army cutworm — the larva of a noctuid moth, Chorizagrotis auxiliaris, that is a pest of wheat and alfalfa in the Plains states.
- army officer — a person in the army who holds a position of authority, responsibility and duty, especially one who holds a commission
- aromatherapy — Aromatherapy is a type of treatment which involves massaging the body with special fragrant oils.
- aromatically — having an aroma; fragrant or sweet-scented; odoriferous.
- around about — Around about means approximately.
- arousability — to stimulate sexually.
- arpeggiation — the writing, playing or singing of arpeggios
- array theory — (theory) A theory developed by Trenchard More Jr. and used as the basis for the NIAL language. Papers are available from the IBM Cambridge Scientific Center, Cambridge MA.
- arseniferous — Lb geology Containing or producing arsenic.
- arseno group — the bivalent group −As=As−.
- arsenopyrite — a white or grey metallic mineral consisting of a sulphide of iron and arsenic that forms monoclinic crystals with an orthorhombic shape: an ore of arsenic. Formula: FeAsS
- arsino group — the univalent group H 2 As−.
- arson attack — an attack when property is set fire to
- art director — a person responsible for the sets and costumes in a film