English Words Starting With O

• onion fly

  nounSpecialist / C1
  /ˈʌn.jən ˌflaɪ/A small fly whose larvae (maggots) infest and damage onion plants.
• onion rings

  plural-nounB1
  /ˈʌn.jən ˌrɪŋz/A food consisting of rings of onion that are coated in batter or breadcrumbs and deep-fried.
• onion snow

  nounVery Low (Regional/Dialectal)
  /ˈʌnjən snəʊ/A late spring snow that falls after onions have been planted, or when spring crops are emerging.
• onion weed

  nounLow
  /ˈʌnjən ˌwiːd/A wild perennial plant of the genus Nothoscordum or Allium, often considered invasive and having onion-like leaves and small bulbs.
• onions

  nounHigh
  /ˈʌn.jənz/The plural form of 'onion', referring to the edible bulb of a plant from the genus Allium, characterized by a strong smell and pungent taste, commonly used as a vegetable or flavouring in cooking.
• onionskin

  nounC1
  /ˈʌn.jən.skɪn/A very thin, lightweight, translucent paper, originally made from the outer layers of onions but now typically a type of high-quality, smooth, lightweight paper.
• onitsha

  nounVery Low
  /ɒˈnɪtʃə/A city and port in southeastern Nigeria, on the Niger River, an important commercial and cultural hub.
• onium compound

  nounC2
  /ˈəʊ.ni.əm ˈkɒm.paʊnd/A positively charged ion (cation) formed by the addition of a proton (H⁺) to a neutral molecule, or more broadly, any cation derived by adding a proton or alkyl group to a Lewis base (like ammonia, phosphine, or sulfide).
• onkelos

  nounExtremely low/Technical
  /ˈɒŋkəlɒs/A specific, proper noun referring to a historic Aramaic translation (Targum) of the Hebrew Bible.
• onlap

  nounRare (Specialist/Technical)
  /ˈɒnlæp/A geological term describing the relationship between sedimentary rock layers where younger layers progressively extend over the edge of an older, underlying layer.
• onlay

  nounverb-transitiveC1
  /ˈɒnleɪ/A restoration or prosthetic device (e.g., for a tooth) that is cemented onto a prepared surface.
• online catalog

  nounB2
  /ˌɒn.laɪn ˈkæt.ə.lɒɡ/A digital database or website where items (books, products, services, etc.) are systematically listed and described, allowing users to search, browse, and access information remotely via the internet.
• online dictionary

  nounC1
  /ˌɒn.laɪn ˈdɪk.ʃən.ər.i/A dictionary whose content is accessible via the internet, typically providing definitions, pronunciations, and other linguistic information.
• online thesaurus

  nounB2
  /ˌɒnˈlaɪn θɪˈsɔːrəs/A digital dictionary of synonyms and related words accessible via the internet.
• onliner

  nounC2
  /ˈɒnˌlaɪnə/A person who regularly uses the internet, especially for social interaction, shopping, or services.
• onload

  verb-ambitransitiveLow (specialized term in IT/web development contexts)
  /ˈɒnˌləʊd/To load something (typically data, a script, or a page) onto or into a system, or the event triggered when this process is complete.
• onlooker

  nounB2
  /ˈɒnˌlʊkə/A person who watches something happening without being involved in it.
• onnagata

  nounVery Low
  /ˌɒnə ˈɡɑːtə/A male actor who specializes in playing female roles in Japanese kabuki theatre.
• onomasiology

  nounVery Low (C2)
  /ˌɒnə(ʊ)ˌmeɪzɪˈɒlədʒi/The branch of lexicology concerned with the study of concepts and the words or linguistic forms used to name them (the principle of 'name to thing').
• onomasticon

  nounRare
  /ˌɒnəʊˈmæstɪkɒn/A book or list of names, especially of personal names.

Showing 1221–1240 of 3187 words.