Showing 2,001 to 2,100 of 3,132.
- OBOLSynonym of obolus: a silver coin of Ancient Greece.
- OBOLUSA silver coin minted in Ancient Greece, valued at a sixth of a drachma.
- OCEANOne of the large bodies of water separating the continents.
- OCHREA clay earth pigment containing silica, aluminum and ferric oxide.
- OCTAHEDRONa polyhedron with eight faces; the regular octahedron has regular triangles as faces and is one of the Platonic solids.
- OCTAPLAA text presented in eight parallel versions, especially the version of the Bible presented in such a fashion by Origen.
- OCTAPODYA metre or verse of eight feet.
- OCTOPUSAny of several marine molluscs of the order Octopoda, having no internal or external protective shell or bone (unlike the nautilus, squid and cuttlefish) and eight arms each covere
- ODEONAn ancient Greek or Roman building used for performances of music and poetry.
- ODOMETERAn instrument, usually embedded within the speedometer of a vehicle, that measures the distance the vehicle has traveled since production.
- ODONATEAny carnivorous insect of the order Odonata; a dragonfly or damselfly.
- ODONTALGIAtoothache
- ODYLESynonym of od (“a hypothetical force or natural power, now proved not to exist, which was supposed by Carl Reichenbach and others to inhere in certain people and produce phenomena
- ODYSSEYAn extended adventurous voyage, usually in search of home.
- OECISTA founder of a colony.
- OGREA large, grotesque, brutish humanoid monster, typically marked by great strength and a propensity to kill or devour humans.
- OIDIUMA fragile spore produced by some fungi.
- OLEUMA solution of sulfur trioxide in sulfuric acid.
- OLIBANUMA gum resin from trees of the genus Boswellia, formerly used as a medicine and now mainly as incense.
- OLIGAEMIAThe condition of having a low quantity of blood.
- OLIGARCHA member of an oligarchy; someone who is part of a small group that runs a country.
- OLIGARCHYA government run by and for only a few, often the aristocracy, the wealthy, or their friends and associates.
- OLIGURIAA decreased production in the volume of urine.
- OLIPHANTAn elephant.
- OLPEOriginally, a leather flask or vessel for oils or liquids; afterward, an earthenware vase or pitcher without a spout.
- OMEGAThe twenty-fourth letter of the Classical and the Modern Greek alphabet, and the twenty-eighth letter of the Old and the Ancient Greek alphabet, i.e. the last letter of every Greek
- OMOPHAGIAThe eating of raw food, especially raw flesh.
- OMOPHAGICEating raw flesh; using uncooked meat as food.
- OMOPLATEThe scapula.
- OMPHACITEAny of a range of green, monoclinic pyroxene minerals found in eclogites and similar rocks; they are solid solutions of jadeite and diopside.
- OMPHALOIDShaped like a navel.
- OMPHALOSAn ancient religious stone artifact, or baetylus, used to denote the direction of the "center" of the world.
- ONEIRICOf or pertaining to dreams.
- ONOMASTICOf or relating to a personal or place name.
- ONOSSynonym of epinetron (“Attic pottery item”).
- ONTICOntological.
- ONYXA banded variety of chalcedony, a cryptocrystalline form of quartz.
- OOMANCYDivination through the use of eggs.
- OPHICLEIDEA keyed brass baritone bugle, now replaced by the tuba in orchestral music
- OPHIDIANAny species of the suborder Serpentes; a snake or serpent.
- OPHIOLATRYsnake worship
- OPHIOLITEAn assemblage of mafic and ultramafic rock fragments of the ocean lithosphere that has been tectonically moved onto a continental margin or island.
- OPHITEAny of various rocks having snake-like markings, such as a mottled greenish porphyry.
- OPISOMETERA device for measuring the length of curved lines, such as on a map.
- OPSIMATHA person who learns late in life.
- OPSINAny of a group of light-sensitive proteins in the retina.
- OPSIOMETERAn old type of optometer.
- OPTATIVEExpressing a wish or a choice.
- OPTICOf, or relating to the eye or to vision.
- OPTICSThe physics of light and vision: basic optical science.
- ORACHThe saltbush: any of several plants of the genus Atriplex especially Atriplex hortensis or Atriplex patula, found in dry habitats, that have edible leaves resembling spinach.
- ORCHIDA plant of the orchid family (Orchidaceae), bearing unusually-shaped flowers of beautiful colours.
- ORCHISAn orchid; now specifically, a plant of the genus Orchis.
- ORCHITISA painful inflammation of one or both testes.
- OREADA mountain nymph; an anthropomorphic appearance of the spirit of a mountain.
- OREGANOA herb of the mint family, Origanum vulgare, having aromatic leaves.
- OREXINEither of two neuropeptide hormones found in vertebrates; the two are orexin-A and orexin-B.
- OREXISThe affective and conative character of mental activity as contrasted with its cognitive aspect; the appetitive aspect of an act; desire, appetite.
- ORFEA fish, the ide, Leuciscus idus.
- ORGANOLEPTICOf or pertaining to the sensory properties of a particular food or chemical, the taste, colour, odour, and feel.
- ORGANUMA type of medieval polyphony which builds upon an existing plainsong.
- ORGASMA spasm or sudden contraction.
- ORGASMICOf or relating to orgasms.
- ORGIASTOne who attends an orgy.
- ORGIASTICRelating to an orgy; uncontrolled, wild.
- OROGENYThe process of mountain building by the upward folding of the Earth's crust.
- OROIDEAn alloy of copper and zinc or tin that has a gold color, used in making inexpensive jewelry.
- ORTHIANDenoting a type of singing at a very high pitch.
- ORTHOEPYThe study of pronunciation.
- ORTHOPEDIAThe branch of medicine which deals with the prevention and correction of deformities in bodies; orthopedics.
- ORTHOPEDIASThe branch of medicine which deals with the prevention and correction of deformities in bodies; orthopedics.
- ORTHOPEDICSThe branch of medicine that deals with the prevention or correction of disorders of the bones and associated muscles and joints.
- ORYXAny of several antelopes, of the genus Oryx, native to Africa, which have long, straight horns
- OSCHEALPertaining to the scrotum.
- OSTENSIBLEApparent, evident; meant for open display.
- OSTRACIZETo ban a person from a city for five or ten years through the procedure of ostracism.
- OSTRACODAny of many small crustaceans, of the class Ostracoda, that resemble a shrimp enclosed in a bivalve shell.
- OSTRACONA piece of pottery or stone, usually broken off from a vase or other earthenware vessel, especially one used to cast a vote during the Ancient Greek process of ostracism.
- OSTRICHA large flightless bird of the order Struthioniformes. The most widespread species of that order, known as the common ostrich (Struthio camelus).
- OTALGIAearache
- OTARYSynonym of eared seal.
- OTICOf, relating/pertaining to, or located near the ear.
- OTOLITHA small particle, composed mainly of calcium carbonate, found in the inner ear of vertebrates, being part of the balance sense.
- OUGUIYAThe currency of Mauritania, divided into five khoums.
- OUZOAn anise-flavoured aperitif, originating in Greece.
- OXTONGUEBeef tongue (a foodstuff).
- OXYGENThe chemical element (symbol O) with an atomic number of 8 and relative atomic mass of 15.9994. It is a colorless and odorless gas. Sometimes called elemental oxygen to distinguish
- OXYMELA mixture of honey, water, and vinegar, boiled to a syrup, sometimes mixed with herbs or spices.
- OXYNTICProducing acid.
- OXYTOCINA hormone that stimulates contractions during labor, and then the production of milk; also plays a role in social bonding.
- OXYTONEHaving the stress on the last syllable.
- OYSTERAny of certain marine bivalve mollusks, especially those of the family Ostreidae (the true oysters), usually found adhering to rocks or other fixed objects in shallow water along t
- OZONEAn allotrope of oxygen (symbol O₃) having three atoms in the molecule instead of the usual two; it is a toxic gas, generated from oxygen by electrical discharge.
- PAEONICSVerse written in paeons.
- PAGANRelating to, characteristic of religions that differ from main world religions.
- PAIDEUTICSThe science or art of teaching.
- PALFREYA small horse with a smooth, ambling gait, popular in the Middle Ages with nobles and women for riding (contrasted with a warhorse).
- PALINDROMEA word, phrase, number or any other sequence of units which has the property of reading the same forwards as it does backwards, character for character, sometimes disregarding punc
- PALINODEAn ode or other poem in which the author retracts something said in an earlier poem; a recantation.
- PALLADIUMA safeguard.