Word origins

• omnifariousOf many or all forms, varieties, or kinds.
• omniferousThat bears everything; producing all types.
• omnificCapable of making or doing anything; all-creating.
• omnifutuentBisexual.
• omnigenousConsisting of all kinds.
• omniparientProducing or bringing forth all things.
• omnipollentAll-powerful.
• omnispectiveBeholding everything; all-seeing.
• omnisubjugantSubjugating all others.
• omnium-gatherumA collection containing a variety of miscellaneous things.
• omnivagantFree-roaming; travelling everywhere.
• omphalodeThe central part of the hilum of a seed, through which the nutrient vessels pass into the raphe or chalaza.
• oneirologyThe study of dreams and their interpretation.
• oneraryFitted for, or carrying, a burden.
• onerosityOnerousness.
• oneseed juniperA shrub or small tree native to mountains in southwestern North America, Juniperus monosperma
• onocentaurA centaur with the body of an ass, instead of a prototypical horse.
• onocerinA white crystalline waxy triterpene extracted from the root of the leguminous plant spiny restharrow (Ononis spinosa).
• Ontario LacusA large hydrocarbon lake on Titan, the largest moon of the planet Saturn.
• on the horns of a dilemmaFacing a choice between two equally undesirable alternatives.
• opacifyTo make opaque.
• opacousNot shining or illuminated; dark.
• operameterAn instrument or machine for measuring work done, especially the number of rotations by a machine or wheel in manufacturing cloth.
• operculiformHaving the form of a lid or cover.
• opere citatoIn the work (already) cited or quoted. Used, typically in footnotes and endnotes, to cite in an abbreviated form a source that has been cited previously; frequently abbreviated as op. cit.
• operibus citatisIn the works (already) cited or quoted.
• operoseOf a person: busy, industrious, or painstaking.
• operosityLaboriousness; painstakingness.
• ophiteAny of various rocks having snake-like markings, such as a mottled greenish porphyry.
• opiferousBringing help; helpful.
• opificeworkmanship
• opificerA person who creates or makes something.
• opinableCapable of being opined or thought.
• opiparousSumptuous, luxurious.
• opisthotonosSustained tetanic spasm in which the body is bent backwards and stiffened, as produced by various diseases.
• opitulationThe act of helping or aiding; assistance.
• ople treeThe witch hazel.
• opobalsamThe aromatic resinous juice of Commiphora opobalsamum (balm of Gilead).
• oppilationa stopping by redundant matter, i.e. an obstruction in organs, particularly in the lower intestines.
• oppletefull; crowded
• opponeTo oppose.
• oppugnantopposing, antagonistic, contrary
• oppugnationSynonym of opposition.
• opsonicRelating to, produced by, or involving opsonin.
• opsonyAny food that is eaten with bread.
• optableThat may or should be chosen; desirable.
• optimityThe state of being best.
• -orCreates an agent noun, often from a verb, indicating a person or object (often machines or parts of them) that do the verb or part of speech with which they are formed.
• oraculousOracular.
• oransA figure in an attitude of prayer, usually standing, with the elbows close to the sides of the body and with the hands outstretched sideways, palms up.
• orarianOf or pertaining to a coast.
• oratorialoratorical.
• oratoriousoratorical
• orbationThe state of being orbate, or deprived of parents or children; privation, in general; bereavement.
• orbicleA small orb or sphere.
• orbiculaA dorsal sclerite over a hymenopteran arolium; a hard exoskeletal feature with species-specific shape that overhangs and protects the adhesive tip of such an insect's leg and around which the claw(s) curl. Abbreviation "or" or "rb".
• orbitudebereavement or loss of parents or children
• orbuculumA crystal ball.
• ordinativeTending to ordain; directing; giving orders.
• organificMaking an organic or organized structure; producing an organism.
• ornativeA noun case that means "endowed with" or "supplied with".
• ornatureDecoration; ornamentation.
• ornifyTo ornament.
• oro-Of or pertaining to the mouth.
• ortetThe original single parent plant from which a clone ultimately derives.
• ortiveOf or relating to the time or act of rising; eastern.
• -oryAdded to nouns and verbs (often Latinate) to form adjectives meaning “of”, “pertaining to”, or “serving for”.
• oryctognosyKnowledge about things dug up, especially what is now considered mineralogy.
• oryzalinA selective herbicide used to control annual grasses etc. in food crops
• oryzastrobinA particular strobilurin fungicide.
• oryzivorousHaving a diet rich in rice.
• os-Against; facing; a combining prefix found in verbs of Latin origin.
• OscanOf or pertaining to the Oscan language or Oscan people, or their writing system.
• oscineOf or pertaining to songbirds (suborder Passeri).
• oscinineOf or pertaining to the Oscines, or songbirds (birds of the clade Passeri).
• oscitantyawning or gaping
• oscitationThe act of yawning or gaping.
• os clitoridisThe baubellum.
• os coxaeSynonym of hip bone.
• osculantAdhering closely; applied to certain creeping animals, such as caterpillars.
• osculationThe action of kissing.
• -oseFull of; affected by.
• OsiandrianOf or relating to Andreas Osiander (1498–1552), German Lutheran theologian.
• os penisThe baculum.
• ossicleA small bone (or bony structure), especially one of the three of the middle ear.
• ossiferousContaining or yielding bone.
• ossificCapable of producing bone; having the power to change cartilage or other tissue into bone.
• ossilegiumThe collection of the bones of a dead person, after decomposition of the soft tissue, for placement in an ossuary
• ostentTo make an ambitious display of; to exhibit or show boastingly; to ostentate.
• ostraceanAny bivalve of the family Ostreidae; an oyster.
• ostreaceousOf or pertaining to an oyster, or to a shell.
• ostreaphileAn lover or aficionado of oysters as food.
• otiantAt ease, at leisure; idling, indolent.
• otioseHaving no effect.
• otrovertA person who is unable to feel a connection to social groups or collectives, as distinct from both an introvert and an extrovert.
• ottomyA skeleton.
• ovantexultant
• ovariousPertaining to or made up of eggs.
• over the transomOf a work submitted for publication, unsolicited.
• ovi-Egg.