English Words Starting With O

• ookpik

  nounExtremely Low
  /ˈuːkpɪk/A small stuffed owl toy, specifically a snowy owl, originating from Inuit craft and culture.
• oolachan

  nounVery Rare
  /ˈuːləkən/A small, silvery, anadromous fish found in the North Pacific, valued for its high oil content.
• oolite

  nounLow
  /ˈəʊəlʌɪt/A sedimentary rock consisting of small, spherical grains of calcium carbonate.
• oolith

  nounVery Rare
  /ˈəʊ.lɪθ/A small, rounded accretionary body, typically a grain of calcium carbonate, found in certain limestones and sedimentary rocks.
• oology

  nounVery Rare
  /əʊˈɒlədʒi/The study or collection of birds' eggs.
• oolong

  nounLow
  /ˈuːlɒŋ/A type of tea, partially oxidized, traditionally made in China and Taiwan, which has a flavor and color between green and black tea.
• oom

  nounVery Low (Regionally Specific)
  /ʊm/A title of respect used in South African English for an older male, particularly an uncle or elder.
• oom paul

  nounExtremely Low
  /ˌʊm ˈpaʊl/A nickname for Paul Kruger, President of the South African Republic (Transvaal).
• oomiak

  nounVery Low
  /ˈuː.mi.æk/A large, open skin boat traditionally used by Inuit peoples, typically made from a wooden frame covered with walrus or seal skin.
• oompah

  adjectivenounLow
  /ˈʊm.pɑː/The rhythmic, repetitive, deep sound made by brass instruments, especially tubas, in a band, particularly associated with German-style folk or polka music.
• oomph

  nounC1
  /ʊmf/Vital energy, enthusiasm, sex appeal, or striking power; the quality of being exciting, vigorous, or appealing.
• oomycete

  nounVery Rare
  /ˌəʊ.ə(ʊ)ˈmaɪ.siːt/A fungus-like organism belonging to the class Oomycetes, many of which are pathogenic to plants.
• oomycota

  plural-nounVery Low
  /ˌəʊ.ə(ʊ)ˈmaɪ.kəʊ.tə/A distinct group of fungus-like organisms, known as water molds, that are filamentous, absorptive, and include important plant pathogens like downy mildews and Phytophthora.
• oona

  nounVery low
  /ˈuːnə/A female given name, typically of Irish origin.
• oont

  nounExtremely Rare / Archaic
  /uːnt/A camel. Primarily military slang from British colonial India.
• oophorectomy

  nounC2
  /ˌəʊ.ə.fəˈrek.tə.mi/The surgical removal of one or both ovaries.
• oophoritis

  nounVery Low
  /ˌəʊ.ə.fəˈraɪ.tɪs/Inflammation of one or both ovaries.
• oophyte

  nounVery Rare (C2+)
  /ˈəʊə(ʊ)fʌɪt/In botany, the gametophyte stage (sexual phase) of ferns, mosses, and related plants, which produces reproductive cells.
• oort

  nounVery Low
  /ɔːt/A proper noun referring to a theoretical, spherical cloud of icy planetesimals believed to surround the Solar System at a great distance, named after the Dutch astronomer Jan Hendrik Oort.
• oort cloud

  nounVery Low
  /ˈɔːt ˌklaʊd/A theoretical, spherical shell of icy objects, mainly comets, believed to surround the solar system at an immense distance.

Showing 1281–1300 of 3187 words.