English Words Starting With O

• onomastics

  nounC2
  /ˌɒn.əˈmæs.tɪks/The study of the origin, history, and use of proper names, especially personal names and place names.
• onomatology

  nounC2
  /ˌɒn.ə.məˈtɒl.ə.dʒi/The study of the formation, history, and meaning of proper names.
• onomatopoeia

  nounC2
  /ˌɒnəˌmætəˈpiːə/A word that phonetically imitates, resembles or suggests the sound that it describes.
• onondaga

  nounC1/C2 (Low-frequency, culturally/geographically/historically specific term)
  /ˌɒnənˈdɑːɡə/Proper noun referring to a Native American people (the Onondaga Nation), a member of this people, or their Iroquoian language.
• onrush

  nounC1
  /ˈɒn.rʌʃ/a sudden, powerful, and often violent forward movement or flow of something.
• onsager

  nounVery Low
  /ˈɒnsɑːɡə/A proper noun referring to Lars Onsager (1903–1976), a Norwegian-American physical chemist and Nobel laureate.
• onset

  nounC1
  /ˈɒn.set/The beginning or start of something, especially something unpleasant or impactful.
• onshore

  adjectiveadverbverb-ambitransitiveB2
  /ˌɒnˈʃɔː/Located on or moving toward the land (from the sea); operating within a country's borders.
• onshoring

  nounLow to medium
  /ˈɒn.ʃɔː.rɪŋ/The practice of moving business operations, especially manufacturing or services, back to the company's home country from overseas.
• onside kick

  nounC2
  /ˈɒn.saɪd ˈkɪk/A legal kick in American or Canadian football where the ball is kicked a short distance along the ground to allow the kicking team a chance to recover it, as long as the kicker's teammates are behind the ball at the moment of the kick.
• onslaught

  nounC1
  /ˈɒn.slɔːt/A fierce or destructive attack, either physical or figurative.
• onslow

  nounVery Low
  /ˈɒnzləʊ/A proper noun, most commonly a surname or the name of various places (e.g., a county in North Carolina, a suburb in Sydney).
• ontarian

  adjectivenounC1/C2
  /ɒnˈtɛːrɪən/A native or inhabitant of Ontario, Canada; of, relating to, or characteristic of the province of Ontario.
• ontario

  nounHigh
  /ɒnˈtɛə.ri.əʊ/A province in east-central Canada; the most populous Canadian province.
• onto function

  nounVery Low
  /ˌɒn.tuː ˈfʌŋk.ʃən/A function where every element of the function's codomain is the image of at least one element from its domain.
• ontogeny

  nounC2
  /ɒnˈtɒdʒəni/The development of an individual organism from the earliest stage to maturity.
• ontological argument

  nounC2
  /ˌɒn.təˈlɒdʒ.ɪ.kəl ˈɑːɡ.jə.mənt/A philosophical argument for the existence of God based on the very concept or definition of God as a maximally perfect being.
• ontologism

  nounVery Low (Rare)
  /ɒnˈtɒlədʒɪz(ə)m/A philosophical or theological theory that posits the direct intuitive knowledge of God or being as the foundation of all human knowledge.
• ontologize

  verb-transitiveVery Low (C2)
  /ɒnˈtɒlədʒaɪz/To treat something as having a real existence or essence, or to express it in terms of ontology.
• ontology

  nounC2
  /ɒnˈtɒlədʒi/The branch of metaphysics dealing with the nature of being, existence, or reality; a particular theory about the nature of being or the kinds of things that exist.

Showing 1241–1260 of 3187 words.