English Words Starting With F

• ferly

  adjectivenounverbObsolete/Rare
  /ˈfɜːli/A strange, marvelous, or unexpected sight or event; something that causes wonder or astonishment.
• fermanagh

  nounC2
  /fərˈmænə/A county in Northern Ireland, named after the Gaelic term 'Fir Manach' meaning 'Men of Manach'.
• fermat

  nounC2
  /ˈfɜːmæt/The fundamental, definitive, or irreducible quality or state of something; a foundational principle or core essence.
• fermat's last theorem

  nounC2 (Very Low Frequency)
  /ˌfɜː.mɑːz ˈlɑːst ˈθɪə.rəm/A famous unsolved conjecture in number theory, proposed by Pierre de Fermat in 1637, stating that no three positive integers a, b, and c can satisfy the equation aⁿ + bⁿ = cⁿ for any integer value of n greater than 2.
• fermat's principle

  nounC2 (Proficient/Technical)
  /ˈfɛəmɑːz ˈprɪnsɪpəl/ (FER-mahz PRIN-suh-puhl)In optics and classical mechanics, the principle that the path taken by a ray of light between two points is the path that can be traversed in the least time. It's a variational principle stating that light travels along the path of stationary optical path length (not always strictly minimal, but extremal).
• fermat's theorem

  nounC2
  /ˌfɛəmɑːz ˈθɪərəm/A theorem in number theory, most famously Fermat's Last Theorem, which states that no three positive integers a, b, and c satisfy the equation aⁿ + bⁿ = cⁿ for any integer value of n greater than 2.
• fermata

  nounC2/Technical
  /fəˈmɑːtə/A musical symbol indicating that a note or rest should be prolonged beyond its normal duration, at the performer's discretion.
• ferment

  nounverbverb-intransitiveverb-transitiveC1
  /fəˈment/ (verb), /ˈfɜː.ment/ (noun)To undergo or cause to undergo fermentation, a chemical process where microorganisms break down organic substances, often producing gases or alcohol.
• fermentation

  nounC1
  /ˌfɜː.menˈteɪ.ʃən/A chemical process in which microorganisms like yeast or bacteria break down organic substances (typically sugars) into simpler substances (like alcohol, acids, or gases), often producing energy and causing effervescence and heat.
• fermentation lock

  nounVery Low
  /ˌfɜː.menˈteɪ.ʃən lɒk/A device, typically a water-filled airlock, used in fermentation vessels to allow gases to escape while preventing outside air and contaminants from entering.
• fermi

  nounC2
  /ˈfəːmi/A unit of length equal to one quadrillionth (10^-15) of a metre, used especially in particle and nuclear physics; also, a surname of the physicist Enrico Fermi.
• fermi energy

  nounC1-C2
  /ˈfɜːmi ˈɛnədʒi/The highest occupied energy level in a system of fermions (like electrons) at absolute zero temperature.
• fermi-dirac statistics

  nounplural-nounC2
  /ˌfɜː.mi dɪˈræk stəˈtɪs.tɪks/The statistical mechanics of a collection of identical, indistinguishable particles that obey the Pauli exclusion principle, such as electrons, protons, and neutrons.
• fermion

  nounC2
  /ˈfɜː.mi.ɒn/A type of elementary particle that follows Fermi-Dirac statistics and obeys the Pauli exclusion principle.
• fermium

  nounExtremely Rare
  /ˈfəːmɪəm/A synthetic, highly radioactive metallic chemical element (symbol Fm, atomic number 100) in the actinide series.
• fermor

  nounExtremely Low / Archaic
  N/AA rare term, not found in standard modern English dictionaries. Historically, it is an obsolete variant spelling of the word 'farmer'.
• fern

  nounC1
  /fɜːn/A non-flowering vascular plant with feathery or leafy fronds, reproducing via spores.
• fern bar

  nounLow
  /ˈfɜːn ˌbɑː/A type of bar or pub that was popular in the United States from the 1970s to the 1990s, characterized by abundant plant decor (often ferns), brass fixtures, and upscale, casual dining.
• fern root

  nounLow
  /fɜːn ruːt/The underground, typically rhizomatous, part of a fern plant, from which fronds grow and which anchors the plant and absorbs nutrients.
• fern seed

  nounLow
  /ˈfɜːn ˌsiːd/The minute, dust-like spores produced by ferns for reproduction.

Showing 1261–1280 of 5868 words.