English Words Starting With U

• ultrahigh frequency

  nounC2
  /ˌʌl.trəˌhaɪ ˈfriː.kwən.si/A band of radio waves with extremely short wavelengths and very high frequencies.
• ultraism

  nounLow
  /ˈʌl.trə.ɪ.zəm/An extreme or uncompromising adherence to principles, often in a political or ideological context.
• ultralarge crude carrier

  nounC2 (Proficiency)
  /ˌʌl.trəˌlɑːʤ ˌkruːd ˈkæ.ri.ə/A type of ship, a Very Large Crude Carrier (VLCC), used specifically for transporting vast quantities of unrefined oil.
• ultraleft

  adjectivenounRare
  /ˌʌl.trə.ˈleft/A political position or group that is extremely left-wing, often associated with revolutionary or radical socialist ideologies.
• ultraleftist

  adjectivenounLow
  /ˌʌltrəˈlɛftɪst/A person holding extremely radical left-wing political views.
• ultraliberal

  adjectivenounlow
  /ˌʌltrəˈlɪbərəl/Extremely liberal, especially in political or social views.
• ultralight

  adjectivenounC1
  /ˌʌl.trəˈlaɪt/Extremely lightweight; having a weight far below the standard for its category, often relating to aircraft, materials, or equipment.
• ultralow frequency

  nounC2
  /ˌʌl.trə.ləʊ ˈfriː.kwən.si/A radio frequency band between 300 Hz and 3 kHz, used for specialized communication.
• ultramarathon

  nounC1
  /ˈʌltrəˌmærəθən/Any foot race longer than the standard marathon distance of 42.195 kilometres (26.219 miles).
• ultramarine

  adjectivenounC2
  /ˌʌl.trə.məˈriːn/A brilliant deep blue pigment originally made from crushed lapis lazuli, or the colour itself.
• ultrametamorphism

  nounExtremely rare (CEFR level C2)
  /ˌʌl.trə.met.əˈmɔː.fɪ.zəm/An extreme degree of metamorphism in geology, where rocks undergo profound mineralogical and textural transformation under exceptionally high temperatures and pressures, typically exceeding those of normal regional metamorphism.
• ultramicrobalance

  nounVery low
  /ˌʌltrəˌmaɪkrəʊˈbæləns/A highly sensitive balance used for measuring extremely small masses, typically in the microgram range.
• ultramicrochemistry

  nounVery low
  /ˌʌl.trəˌmaɪ.krəʊˈkem.ɪ.stri/The branch of chemistry dealing with extremely small quantities of substances, typically less than a milligram.
• ultramicrofiche

  nounLow
  /ˌʌltrəmaɪˈkrəʊfɪʃ/A type of microfiche that is extremely small, used for high-density storage of documents.
• ultramicrometer

  nounVery Low / Technical Only
  /ˌʌltrəmaɪˈkrɒmɪtə/An instrument for measuring extremely small distances (typically on the order of microns or less), beyond the capability of an ordinary micrometer.
• ultramicroscope

  nounC2 (Very low frequency, highly specialized)
  /ˌʌltrəˈmaɪkrəskəʊp/A microscope that uses scattered light to make very small particles visible (those below the resolution limit of a standard optical microscope).
• ultramicroscopy

  nounC2
  /ˌʌltrəmaɪˈkrɒskəpi/A microscopy technique that enables the observation of particles smaller than the wavelength of light, typically using dark-field illumination.
• ultramicrotome

  nounVery Low
  /ˌʌltrəˈmaɪkrəˌtəʊm/A precision instrument used to cut extremely thin sections of material, typically for examination under an electron microscope.
• ultraminiaturize

  verb-transitiveLow
  /ˌʌltrəˈmɪnɪətʃəraɪz/To make something extremely small through advanced miniaturization techniques.
• ultramontane

  adjectivenounVery Low
  /ˌʌl.trəˈmɒn.teɪn/A strong supporter of the Pope's supreme authority, especially in matters of Church doctrine and jurisdiction.

Showing 141–160 of 1514 words.