11-letter words containing a, t, o, r
- aortography — an X-ray examination of the aorta
- apatosaurus — brontosaurus
- apertometer — an instrument for measuring the angular and numerical aperture of the objective lens of a microscope.
- apodyterium — the changing room in an ancient Roman bathhouse
- apoferritin — a homogeneous protein, found especially in the intestinal mucosa and the liver, that interacts with a ferric hydroxide-ferric phosphate complex to form ferritin.
- aponeurotic — a whitish, fibrous membrane that connects a muscle to a bone or fascia.
- apoproteins — Plural form of apoprotein.
- apostlebird — an omnivorous bird, Struthidea cinerea, of eastern Australia, that has chiefly dark gray-brown plumage with white tail markings and is noted for its habit of traveling in groups of about 12 related individuals.
- apostrophes — Plural form of apostrophe.
- apostrophic — a digression in the form of an address to someone not present, or to a personified object or idea, as “O Death, where is thy sting?”.
- apostrophus — a symbol resembling a reversed letter C used in Roman numerals to denote large numbers
- apotropaism — the use of ritual or magic to ward off evil or bad luck
- apparations — Plural form of apparation.
- apparitions — Plural form of apparition.
- applicators — Plural form of applicator.
- applicatory — suitable for application
- apportioned — to distribute or allocate proportionally; divide and assign according to some rule of proportional distribution: to apportion expenses among the three men.
- apportioner — to distribute or allocate proportionally; divide and assign according to some rule of proportional distribution: to apportion expenses among the three men.
- apprecation — (obsolete) Earnest prayer; devout wish.
- appreciator — to be grateful or thankful for: They appreciated his thoughtfulness.
- approacheth — Archaic third-person singular form of approach.
- approbating — Present participle of approbate.
- approbation — Approbation is approval of something or agreement to it.
- approbative — showing approbation or approval
- approbatory — approving; expressing approbation.
- appropriate — Something that is appropriate is suitable or acceptable for a particular situation.
- approvement — (obsolete, Old English law) Improvement of common lands by converting them for advantage of the landlord.
- approximant — an articulation in which one articulator is close to another, but not sufficiently so to form a stop or a fricative.
- approximate — An approximate number, time, or position is close to the correct number, time, or position, but is not exact.
- apricot jam — a sweet preserve made from apricots
- aprioristic — belief in, or reliance upon, a priori reasoning, arguments, or principles.
- apron stage — a stage that projects into the auditorium so that the audience sit on three sides of it
- aqua fortis — nitric acid
- aquafortist — a person who makes engravings or etchings through the use of aqua fortis
- arabization — transfer to Arab control
- araeometric — relating to araeometry
- arbitration — Arbitration is the judging of a dispute between people or groups by someone who is not involved.
- arbitrators — Plural form of arbitrator.
- arbor vitae — any of several Asian and North American evergreen coniferous trees of the genera Thuja and Thujopsis, esp Thuja occidentalis, having tiny scalelike leaves and egglike cones
- arborescent — having the shape or characteristics of a tree
- arborvitaes — Plural form of arborvitae.
- arc-boutant — flying buttress.
- archaeocyte — (in sponges) a type of amoebocyte capable of developing into other types of cells, especially reproductive cells.
- archenteron — the cavity within an embryo at the gastrula stage of development that eventually becomes the digestive cavity
- archeometry — the branch of archaeology that deals with the dating of archaeological specimens through specific techniques, as radiocarbon dating and amino-acid dating.
- archicortex — (anatomy) Part of the allocortex, specifically three layered hippocampal cortexes necessary for hippocampus formation.
- architector — (obsolete) An architect.
- archtraitor — A chief or transcendent traitor.
- arctic zone — the section of the earth's surface lying between the Arctic Circle and the North Pole.
- arcticology — the scientific study of the Polar Regions.