English Words Starting With O

• olga

  nounLow (as a common noun; high as a proper name within specific communities)
  /ˈɒlɡə/A female given name of Scandinavian origin, originally from the Old Norse Helga, meaning 'holy', 'blessed'.
• olibanum

  nounVery Low
  /ə(ʊ)ˈlɪbənəm/An aromatic gum resin obtained from trees of the genus Boswellia, used chiefly as incense.
• olicook

  nounExtremely low/Not found
  A rare, obsolete or highly specialized term requiring verification. There is no recognized lexical entry for 'olicook' in major standard dictionaries, suggesting it may be a nonce word, a typographical error, a proper noun, or an extremely obscure technical term.
• oligaemia

  nounVery Low (Technical)
  /ˌɒlɪˈɡiːmɪə/An abnormal reduction in the volume of circulating blood.
• oligarch

  nounC1
  /ˈɒl.ɪ.ɡɑːk/A very rich business leader with great political influence, especially in a country where such influence is held by a small, wealthy group.
• oligarchy

  nounC1
  /ˈɒl.ɪ.ɡɑː.ki/A small group of people having control of a country, organisation, or institution.
• oligocene

  adjectivenounLow
  /ˈɒl.ɪ.ɡə.siːn/A geological epoch within the Paleogene period, lasting from about 34 to 23 million years ago, known for cooler global climates and further diversification of mammals.
• oligochaete

  adjectivenounC2
  /ˈɒl.ɪ.ɡəʊˌkiːt/Any worm of the class Oligochaeta, which includes earthworms and other segmented worms that possess few bristles (chaetae).
• oligoclase

  nounVery Low
  /ˈɒlɪɡə(ʊ)kleɪz/A common mineral belonging to the plagioclase feldspar series, composed primarily of sodium and calcium aluminosilicates.
• oligodendrocyte

  nounC2 (Very Low Frequency - Specialized Technical)
  /ˌɒl.ɪ.ɡəʊˈden.drə.saɪt/A type of glial cell in the central nervous system that produces the myelin sheath which insulates axons, enabling rapid nerve impulse transmission.
• oligodontia

  nounVery Low Frequency
  /ˌɒl.ɪ.ɡəʊˈdɒn.ʃə/A dental condition characterized by the congenital absence of six or more permanent teeth.
• oligogene

  nounVery Low (C2+ / Specialized)
  /ˈɒl.ɪ.ɡəʊ.dʒiːn/A gene that has a major, identifiable effect on a trait or phenotype, often controlled by a small number of genes with large effects, as opposed to polygenes with small additive effects.
• oligomenorrhea

  nounVery Low
  /ˌɒlɪɡəʊˌmɛnəˈriːə/A medical term for infrequent or abnormally light menstrual periods.
• oligomer

  nounC2
  /ˈɒlɪɡəmə/A molecule consisting of a small, finite number of repeating monomer units.
• oligonucleotide

  nounC2
  /ˌɒlɪɡəʊˈnjuːklɪəʊtaɪd/A short, single-stranded sequence of nucleotides (the building blocks of DNA and RNA).
• oligopeptide

  nounLow
  /ˌɒlɪɡəʊˈpɛptaɪd/A short chain of amino acids, typically containing between two and twenty amino acids.
• oligophrenia

  nounRare
  /ˌɒlɪɡəʊˈfriːnɪə/A condition of impaired mental development present from birth or early childhood, characterized by significant limitations in intellectual functioning and adaptive behaviour.
• oligopoly

  nounC2
  /ˌɒl.ɪˈɡɒp.əl.i/A state of limited competition in a market where a small number of sellers dominate.
• oligopsony

  nounC2
  /ˌɒlɪˈɡɒpsəni/A market situation where a small number of large buyers control the demand for a product or service, giving them significant power over sellers and prices.
• oligosaccharide

  nounRare/Very Low
  /ˌɒl.ɪ.ɡəʊˈsæk.ər.aɪd/A carbohydrate molecule composed of a small number (typically 3 to 10) of monosaccharide units (simple sugars) linked together.

Showing 981–1000 of 3187 words.