English Words Starting With O

• open stock

  nounC1
  /ˌəʊ.pən ˈstɒk/Items sold individually, not as part of a set.
• open string

  nounC2
  /ˌəʊ.pən ˈstrɪŋ/On a stringed musical instrument, a string that is played without being pressed (or 'stopped') by a finger against a fret or the fingerboard, producing its natural, fundamental pitch.
• open system

  nounMedium
  /ˌəʊ.pən ˈsɪs.təm/A system that freely exchanges energy, matter, or information with its external environment.
• open texture

  nounC2/Proficient
  /ˌəʊpən ˈtɛkstʃə/The inherent vagueness or flexibility in the application of terms, concepts, or rules, where borderline cases are possible because definitions cannot cover every situation.
• open trailer

  nounB2
  /ˌəʊ.pən ˈtreɪ.lə/A flat platform on wheels, pulled by a vehicle, for transporting goods that are not covered or enclosed by sides or a roof.
• open union

  nounLow
  /ˈəʊpən ˈjuːnjən/A labor union that accepts all workers regardless of their skill level, trade, or employment status, typically without requiring membership in a specific craft or profession.
• open universe

  nounLow. Predominantly used in specialized scientific discourse.
  /ˌəʊpən ˈjuːnɪvɜːs/A cosmological model in which the universe expands forever because its density is insufficient to halt the expansion.
• open university

  nounB2
  /ˌəʊpən ˌjuːnɪˈvɜːsəti/A university with a policy of open admissions, offering flexible distance learning, often to adult students without traditional entry qualifications.
• open up

  verbHigh
  /ˌəʊpən ˈʌp/To make something accessible, available, or revealed; to begin operating or becoming available.
• open verdict

  nounC2
  /ˌəʊpən ˈvɜːdɪkt/A formal finding by a coroner's court or an inquest that the cause of a person's death is unknown or undetermined.
• open-angle glaucoma

  nounLow Frequency
  /ˌəʊpənˌæŋɡl̩ ɡlɔːˈkəʊmə/The most common type of glaucoma, where the drainage angle of the eye is open but fluid does not drain properly.
• open-cut mining

  nounC1+ (Very low frequency, domain-specific)
  /ˌəʊ.pənˈkʌt ˈmaɪ.nɪŋ/A surface mining method where minerals or rock are extracted by excavating an open pit.
• open-end mortgage

  nounC1
  /ˌəʊpən ˈend ˈmɔːɡɪdʒ/A mortgage loan that allows the borrower to draw additional funds up to a specified limit after the initial loan, without needing to renegotiate the entire agreement, typically with a variable interest rate.
• open-heart surgery

  nounB2
  /ˌəʊ.pən ˈhɑːt ˌsɜː.dʒər.i/A major surgical operation in which the heart is stopped and the chest is opened so that the surgeon can operate directly on the heart, often using a heart-lung machine to maintain circulation.
• open-hearth furnace

  nounVery Rare
  /ˌəʊpən ˈhɑːθ ˈfɜːnɪs/A large furnace for producing steel, in which the hearth is open to the flame and the charge is heated directly.
• open-hearth process

  nounC2
  /ˌəʊ.pən ˈhɑːθ ˌprəʊ.ses/A method of steelmaking where pig iron and scrap steel are melted in a shallow, open furnace using a regenerative heating system.
• open-jaw

  nounLow
  /ˌəʊ.pənˈdʒɔː/An air travel itinerary where the passenger departs from and returns to different cities, or where the outbound and return destinations are different.
• open-line

  adjectivenounB2
  /ˌəʊ.pən ˈlaɪn/A direct telephone connection to a radio or television studio, allowing the public to call in and speak live on air.
• open-market operations

  plural-nounC1/C2
  /ˌəʊ.pən ˈmɑː.kɪt ˌɒp.ərˈeɪ.ʃənz/The buying and selling of government securities by a central bank in the open market to control the money supply and interest rates.
• open-reel tape

  nounLow/Technical
  /ˌəʊ.pən ˌriːl ˈteɪp/A magnetic recording tape wound on a spool or reel without a protective casing, which must be manually threaded onto a tape recorder.

Showing 1401–1420 of 3187 words.