12-letter words containing e, s, r, o
- archeologist — archaeology.
- 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).
- archipelagos — Plural form of archipelago.
- 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
- 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
- armed forces — The armed forces or the armed services of a country are its military forces, usually the army, navy, marines, and air force.
- 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
- arteriograms — Plural form of arteriogram.
- arthroscopes — Plural form of arthroscope.
- arthrospores — an isolated vegetative cell that has passed into a resting state, occurring in bacteria and not regarded as a true spore.
- arthrotomies — Plural form of arthrotomy.
- ash-coloured — silver-grey in colour
- aspect ratio — the ratio of width to height of the picture on a television or cinema screen
- assay groove — (in silverwork) a furrow left in a piece by the digging out of metal for assay.
- assertations — Plural form of assertation.
- assessorship — the occupation, post or duties of a person who assesses, advises, or estimates
- 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
- astigmometer — an apparatus for measuring the degree of astigmatism.
- astrochemist — (chemistry, astronomy) A chemist or astronomer whose speciality is astrochemistry.
- astrogeology — the study of the structure, composition, and history of other planets and other bodies in the solar system
- asynchronies — a lack of synchronism or coincidence in time.
- at the worst — bad or ill in the highest, greatest, or most extreme degree: the worst person.
- atheromatous — a sebaceous cyst.
- atholl brose — a mixture of whisky and honey left to ferment before consumption
- atmospherics — Atmospherics are elements in something such as a piece of music or a book which create a certain atmosphere.
- atmospherium — an optical system used to simulate images of atmospheric phenomena, as cloud formations, storms, and day and night, on the inside of a dome.
- atom smasher — accelerator (sense 3)
- attorneyship — The office or profession of an attorney.
- auger shower — a shower of electrons, photons, etc. resulting from the collision of primary cosmic rays with atomic nuclei in the atmosphere
- austronesian — of or relating to Austronesia, its peoples, or their languages
- auto-erotism — the arousal and satisfaction of sexual excitement within or by oneself, as by masturbation.
- autochangers — Plural form of autochanger.
- autodestruct — likely to or possessing the power to destroy or obliterate itself or its possessor
- autodiallers — Plural form of autodialler.
- autoexposure — A device that sets the exposure automatically on a camera or other piece of equipment.
- b chromosome — a type of densely staining chromosome of uncertain biological function, found in many plant and animal species.
- bachelorship — the state of being a bachelor; bachelorhood
- bacon-slicer — a machine for cutting bacon into slices
- bacteriostat — any substance that arrests the growth or reproduction of bacteria but does not kill them
- baker's oven — an oven used esp for baking bread
- banksia rose — a climbing rose, Rosa banksiae, native to China, having long, serrated leaves and white or yellow flowers.
- barge course — the overhang of the gable end of a roof