12-letter words containing e, n, r, o
- antigropelos — waterproof leggings used to protect against mud
- antihydrogen — hydrogen in which the nucleus is an antiproton with an orbiting positron
- antineutrino — the antiparticle of a neutrino; a particle having oppositely directed spin to a neutrino, that is, spin in the direction of its momentum
- antineutrons — Plural form of antineutron.
- antiperiodic — efficacious against recurring attacks of a disease
- antipredator — discouraging or protecting against predators
- antireformer — One who opposes reform.
- antireligion — opposed to religion
- antistrophes — Plural form of antistrophe.
- antitakeover — opposed to or acting against a takeover
- anton sailer — Anton [ahn-tohn] /ˈɑn toʊn/ (Show IPA), ("Toni") 1935–2009, Austrian skier.
- apperception — the attainment of full awareness of a sensation or idea
- appleknocker — Northern U.S. a rustic.
- appreciation — Appreciation of something is the recognition and enjoyment of its good qualities.
- apprehension — Apprehension is a feeling of fear that something bad may happen.
- approachment — (archaic) approach.
- arachnophobe — a person who is afraid of spiders
- araneomorphs — Plural form of araneomorph.
- arborescence — treelike in size and form.
- arc cosecant — the angle, measured in radians, that has a cosecant equal to a given number. Symbol: csc −1. Abbreviation: arc csc;
- archdeaconry — the office, rank, or duties of an archdeacon
- archdiocesan — Relating to an archdiocese.
- archegoniate — having archegonia
- archenterons — Plural form of archenteron.
- archibenthos — the ocean bottom between the littoral and abyssal zones: from depths of approximately 200 feet (60 meters) to 3300 feet (1000 meters).
- 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
- 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)
- 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
- ariel sharon — Ariel, 1928–2014, Israeli military and political leader; prime minister 2001–06.
- 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
- aristotelian — of or relating to Aristotle or his philosophy
- arpeggiation — the writing, playing or singing of arpeggios
- 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
- assertations — Plural form of assertation.
- asseveration — the act of asseverating.
- assortedness — the position of being sorted, grouped or harmonized with, well or badly, or provided with a good or bad assortment or mixture
- asynchronies — a lack of synchronism or coincidence in time.
- attenborough — Sir David. born 1926, British naturalist and broadcaster; noted esp for his TV series Life on Earth (1978), The Living Planet (1983), The Life of Birds (1998), The Life of Mammals (2002), and First Life (2010)
- attorneyship — The office or profession of an attorney.
- au contraire — on the contrary
- auctioneered — Simple past tense and past participle of auctioneer.
- auroral zone — the region surrounding the north or south geomagnetic pole in which the auroral phenomena take place.
- austronesian — of or relating to Austronesia, its peoples, or their languages
- autoanalyzer — any of various automatic devices that test and analyze chemicals, blood, etc.
- autochangers — Plural form of autochanger.
- autoinjector — A medical device designed to deliver a single dose of a particular, typically life-saving, drug.
- averruncator — a long pair of shears used for pruning the higher branches of trees