English Words Starting With N

• nuclear reactor

  nounC1
  /ˌnjuː.klɪə riˈæk.tə/A device or structure that initiates and controls a self-sustaining nuclear chain reaction for energy production or research.
• nuclear regulatory commission

  nounLow (specialised)
  /ˈnjuː.kli.ə ˌreɡ.jəˈleɪ.tə.ri kəˈmɪʃ.ən/The independent agency of the United States government responsible for regulating civilian uses of nuclear materials to protect public health, safety, and the environment.
• nuclear test-ban treaty

  nounLow
  /ˌnjuː.klɪə(r) ˈtest bæn ˌtriːti/A formal agreement between nations to prohibit the testing of nuclear weapons.
• nuclear threshold

  nounC1/C2
  /ˌnjuː.kli.ə ˈθreʃ.həʊld/The point at which a conflict escalates from conventional to nuclear weapons use.
• nuclear transfer

  nounC2
  /ˌnjuː.klɪə ˈtræns.fɜː/A laboratory technique where the nucleus is removed from one cell and transferred into another cell whose own nucleus has been removed.
• nuclear warhead

  nounC1
  /ˌnjuː.klɪə ˈwɔː.hed/The explosive part of a missile, bomb, or torpedo that uses nuclear fission or fusion to create a massive destructive blast.
• nuclear waste

  nounC1-C2
  /ˌnjuː.kli.ə ˈweɪst/Radioactive and hazardous material that remains from the use of nuclear reactors and the production of nuclear weapons.
• nuclear weapon

  nounC1
  /ˌnjuː.klɪə ˈwep.ən/An explosive device deriving its destructive force from nuclear reactions, either fission (atomic bomb) or a combination of fission and fusion (thermonuclear bomb).
• nuclear weapon state

  nounC1/C2
  /ˌnjuː.klɪə ˈwep.ən steɪt/A sovereign state that has developed and possesses nuclear weapons.
• nuclear winter

  nounC1-C2 / Low
  /ˌnjuː.kli.ə ˈwɪn.tə/A hypothetical period of prolonged, severe cold and darkness on Earth, predicted to follow a large-scale nuclear war.
• nuclear-free zone

  nounC2
  /ˌnjuː.klɪə.friː ˈzəʊn/An area or region, often established by treaty or policy, where nuclear weapons are banned and nuclear activities such as power generation, testing, or deployment are prohibited.
• nuclearism

  nounC2/Very Low
  /ˈnjuː.klɪə.rɪ.zəm/The advocacy of, or reliance on, the possession and potential use of nuclear weapons as a national policy.
• nuclearize

  verb-transitiveC2 (Very Low Frequency / Specialized)
  /ˈnjuː.klɪə.raɪz/To equip or supply with nuclear weapons or technology.
• nuclease

  nounLow
  /ˈnjuː.kli.eɪz/An enzyme that cleaves the phosphodiester bonds between nucleotides in nucleic acids (DNA or RNA).
• nucleate

  adjectiveverbverb-intransitiveverb-transitiveLow (C2)
  /ˈnjuːklɪeɪt/To form or act as a nucleus; to provide an initial center around which something grows or develops.
• nucleating agent

  nounLow
  /ˈnjuː.kli.eɪ.tɪŋ ˈeɪ.dʒənt/A substance introduced into a system to initiate and control the formation of nuclei, which are the initial structures from which crystals or other phases grow.
• nuclei

  nounB2
  /ˈnjuː.kli.aɪ/The plural form of 'nucleus', referring to the central and most important parts of objects or systems.
• nucleic acid

  nounC2 (Academic/Technical)
  /njuːˌkliː.ɪk ˈæs.ɪd/A complex organic substance present in all living cells, forming the genetic material (DNA or RNA).
• nuclein

  nounC2
  /ˈnjuːklɪɪn/An acidic protein complex found in the nucleus of a cell, a historical term for what are now known as nucleic acids or nucleoproteins.
• nucleocapsid

  nounC2
  /ˌnjuːklɪəʊˈkæpsɪd/The protein coat (capsid) that encloses and protects the nucleic acid (genome) of a virus.

Showing 3161–3180 of 3475 words.