English Words Starting With O

• odontoglossum

  nounVery Low
  /əʊˌdɒntəˈɡlɒsəm/A type of orchid, particularly one from a genus (Odontoglossum) found in mountainous regions of Central and South America, known for its showy, often intricately patterned flowers.
• odontograph

  nounVery rare / Technical
  /əʊˈdɒn.tə.ɡrɑːf/A historical instrument for recording the contours of teeth or gear teeth.
• odontoid process

  nounC2
  /əʊˈdɒntɔɪd ˈprəʊsɛs/The tooth-like upward projection of the second cervical vertebra (the axis), around which the first vertebra (the atlas) rotates.
• odontolite

  nounRare / Obsolete
  /əʊˈdɒntəlaɪt/A mineral, a blue or green variety of fossil bone or dentine (often from mammoth teeth) that has been coloured by phosphate of iron; also called bone turquoise.
• odontology

  nounC2 (Very Low Frequency)
  /ˌɒdɒnˈtɒlədʒi/The scientific study of the structure, development, and diseases of teeth.
• odontophore

  nounVery Low
  /əʊˈdɒn.tə.fɔː(r)/A specialised anatomical structure found in certain molluscs (e.g., snails, slugs) that supports the radula, a tongue-like organ covered in rows of microscopic teeth used for feeding.
• odor

  nounB2
  /ˈəʊdə(r)/A distinctive smell, especially an unpleasant one.
• odorant

  nounLow
  /ˈəʊdərənt/A substance that has a smell; something that emits an odour.
• odorimetry

  nounVery Rare
  /ˌəʊ.dərˈɪm.ɪ.tri/The measurement of odors or smells, especially using a scientific instrument.
• odoriphore

  nounVery Low
  /ˈəʊdərɪfɔː/A chemical group or structural element within a molecule that is primarily responsible for the characteristic odor of a compound.
• odorize

  verb-transitiveC2/Technical
  /ˈəʊdərʌɪz/To add an odor or scent to something, typically to make it detectable or to mask an existing smell.
• odour

  nounC1
  /ˈəʊdə(r)/a distinctive smell, especially an unpleasant one
• odour of sanctity

  nounC2
  /ˈəʊdə(r) əv ˈsæŋktəti/A sweet or pleasant smell said to emanate from the body of a saint or holy person after death, considered a sign of their holiness.
• odovacar

  nounVery Low
  /ˌɒdəʊˈveɪkə/A 5th-century Germanic leader who deposed the last Western Roman Emperor and became King of Italy (476–493 AD).
• odra

  nounVery low
  /ˈəʊdrə/The Czech name for the Oder River, a major river in Central Europe.
• odyl

  nounObsolete
  /ˈɒdɪl/A hypothetical vital force or ethereal fluid believed (in historical theories) to emanate from all things and to be the medium of magnetic and hypnotic phenomena.
• odysseus

  nounLow
  /əˈdɪsɪəs/The legendary Greek king of Ithaca, hero of Homer's epic poem the Odyssey, known for his cunning, intelligence, and long, eventful journey home after the Trojan War.
• odyssey

  nounC1
  /ˈɒd.ɪ.si/A long, eventful, and often arduous journey or experience.
• oe

  abbreviationnounLow / Very Rare (Outside of specific contexts)
  /əʊ/ (as in 'go') or /iː/ (in abbreviation 'OE')A small island (chiefly in Scottish place names).
• oecology

  nounVery Low
  /iːˈkɒlədʒi/The scientific study of the relationships between living organisms and their physical environment; the branch of biology dealing with these relationships.

Showing 481–500 of 3187 words.