English Words Starting With N

• nucleoid

  adjectivenounC2
  /ˈnjuːklɪɔɪd/The irregularly-shaped region within a prokaryotic cell (e.g., a bacterium) that contains most or all of the genetic material (DNA), not enclosed by a nuclear membrane.
• nucleolus

  nounC2
  /ˌnjuːkliˈəʊləs/A small, dense structure found inside the nucleus of a cell.
• nucleon

  nounLow
  /ˈnjuːklɪɒn/A proton or neutron, a particle found in the nucleus of an atom.
• nucleon number

  nounLow
  /ˈnjuːklɪɒn ˌnʌmbə/The total number of protons and neutrons in an atomic nucleus.
• nucleonics

  nounC2
  /ˌnjuː.kliˈɒn.ɪks/The branch of physics and technology concerned with atomic nuclei and nuclear energy, including nuclear reactors and nuclear weapons.
• nucleoplasm

  nounC2
  /ˈnjuːkliə(ʊ)ˌplaz(ə)m/The viscous, gel-like substance found within the nucleus of a eukaryotic cell, excluding the nucleolus.
• nucleoprotein

  nounC2
  /ˌnjuː.klɪ.əʊˈprəʊ.tiːn/A type of protein that is chemically combined with nucleic acid (DNA or RNA).
• nucleosidase

  nounVery Low
  /ˌnjuː.kli.əʊˈsaɪ.deɪz/An enzyme that catalyzes the hydrolysis of a nucleoside into its component parts: a nitrogenous base (like adenine or guanine) and a sugar (ribose or deoxyribose).
• nucleoside

  nounC2 (Academic/Technical)
  /ˈnjuːkliəsaɪd/A compound consisting of a nucleobase (e.g., adenine, guanine) linked to a sugar molecule (ribose or deoxyribose) but without a phosphate group.
• nucleosome

  nounC2
  /ˈnjuː.klɪ.əˌsəʊm/The basic structural unit of DNA packaging in eukaryotic cells, consisting of a segment of DNA wound around a core of histone proteins.
• nucleosynthesis

  nounRare
  /ˌnjuː.klɪ.əʊˈsɪn.θə.sɪs/The process by which new atomic nuclei are formed from pre-existing protons and neutrons.
• nucleotide

  nounC2/Advanced
  /ˈnjuːklɪətaɪd/A compound consisting of a nucleoside linked to a phosphate group, forming the basic structural unit of nucleic acids like DNA and RNA.
• nucleus

  nounB2
  /ˈnjuː.kli.əs/The central and most important part of an object, group, or system; the core.
• nuclide

  nounC2+ / Very low (highly specialized)
  /ˈnjuːklaɪd/A distinct type of atom or nucleus characterized by its specific number of protons and neutrons.
• nuddy

  nounVery Low
  /ˈnʌdi/A chiefly British, informal and humorous term for being nude or in the nude; often used playfully or to describe a state of nakedness.
• nude

  adjectivenounB2
  /njuːd/A naked human figure, especially in art; the state of being naked.
• nude descending a staircase

  nounVery Low
  /njuːd dɪˈsendɪŋ ə ˈsteəkeɪs/The title of Marcel Duchamp's famous 1912 Cubist/Futurist painting, which depicts a mechanized, abstracted figure in motion.
• nude mouse

  nounVery Low
  /njuːd maʊs/A special laboratory mouse with a severe combined immune deficiency, lacking hair, and having no functional thymus.
• nudge

  nounverbverb-intransitiveverb-transitiveB2
  /nʌdʒ/A gentle push with the elbow to draw someone's attention, or a slight physical force to move something.
• nudibranch

  nounC2
  /ˈnjuːdɪbræŋk/A marine mollusc of the suborder Nudibranchia, lacking a shell and having exposed gills; a sea slug.

Showing 3181–3200 of 3475 words.