English Words Starting With O

• orthopyroxene

  nounVery low
  /ˌɔːθəʊpaɪˈrɒksiːn/A group of silicate minerals belonging to the pyroxene family, characterized by an orthorhombic crystal structure.
• orthorexia

  nounLow
  /ˌɔː.θəˈrek.si.ə/An unhealthy obsession with eating foods one considers healthy, often leading to malnutrition and social isolation.
• orthoscope

  nounC2 / Extremely Rare / Technical Term
  /ˈɔːθəˌskəʊp/An instrument for examining the eye, especially the interior of the eye, with minimal distortion from the cornea.
• orthoselection

  nounVery Low (C2/Expert)
  /ˌɔːθəʊsɪˈlɛkʃ(ə)n/A mode of natural selection that pushes a population's traits toward a consistent, optimal adaptation within a stable environment, often leading to evolutionary refinement rather than diversification.
• orthosis

  nounLow
  /ɔːˈθəʊsɪs/An external medical device designed to support, align, prevent, or correct deformities or improve the function of movable parts of the body.
• orthostat

  nounC2
  /ˈɔːθəʊstæt/A large, upright stone slab or block, typically used in ancient architecture as a facing stone or in megalithic structures.
• orthostates

  nounC2
  /ˈɔːθəʊsteɪts/In classical architecture, upright stone slabs or blocks, typically used as the lower course of a wall, standing on their long edges.
• orthostatic hypotension

  nounLow
  /ˌɔː.θəˌstæt.ɪk ˌhaɪ.pəʊˈten.ʃən/A sudden fall in blood pressure that occurs when a person stands up.
• orthostichy

  nounVery low
  /ɔːˈθɒstɪki/A vertical row or arrangement of plant parts (especially leaves) along a stem, forming a specific geometric pattern.
• orthotic

  adjectivenounC2
  /ɔːˈθɒtɪk/A device designed to support, align, or correct a body part, especially the foot.
• orthotics

  nounC2
  /ɔːˈθɒt.ɪks/The branch of medicine dealing with the design and fitting of supportive devices (braces or splints) for the body.
• orthotist

  nounVery Low
  /ˈɔːθətɪst/A healthcare professional who designs, fabricates, and fits orthopedic braces and supports (orthoses) for patients.
• orthotone

  adjectivenounVery low
  /ˈɔːθətəʊn/A word that retains its own accent when standing alone or in combination; a word that does not become enclitic or proclitic.
• orthotropism

  nounC2
  /ɔːˈθɒtrəpɪz(ə)m/The directional growth of a plant in response to gravity, typically with the main stem growing vertically upward and roots downward.
• orthros

  nounVery low (Specialized Religious)
  /ˈɔːθrɒs/The morning prayer service or office in the Eastern Orthodox and Eastern Catholic Churches.
• ortler

  nounVery Low (C2)
  /ˈɔːtlə/The highest peak in the Ortler Alps, a mountain range.
• ortles

  plural-nounExtremely rare / obsolete
  /ˈɔːt(ə)lz/A dialectal or obsolete term for the remains of a meal; scraps or leftovers.
• ortolan

  nounVery low
  /ˈɔːtələn/A small, migratory European songbird (Emberiza hortulana) known for its fine flesh, historically considered a delicacy.
• orton

  nounVery Low
  /ˈɔː.tən/A proper noun, typically a surname or place name.
• orts

  plural-nounVery rare
  /ɔːts/Leftover fragments of food; scraps; leavings.

Showing 2101–2120 of 3187 words.