English Words Starting With F

• fibonacci sequence

  nounLow
  /ˌfɪbəˈnɑːtʃi ˈsiːkwəns/An infinite sequence of numbers in which each number (after the first two) is the sum of the two preceding numbers, typically starting with 0 and 1.
• fibranne

  nounLow
  /ˈfʌɪbran/A type of artificial textile fibre made from regenerated cellulose, similar to rayon, but produced with a different manufacturing process that yields a softer, wool-like texture.
• fibre

  nounB1
  /ˈfaɪ.bər/A thin, thread-like structure, either natural (from plants, animals) or artificial, forming part of a material's composition or serving as a basic structural unit.
• fibre optics

  nounC1/C2
  /ˌfaɪ.bər ˈɒp.tɪks/The technology of transmitting information, such as data or voice, as pulses of light through thin, flexible glass or plastic fibres.
• fibreboard

  nounC1
  /ˈfaɪ.bə.bɔːd/A building material made by compressing wood fibres or other plant fibres into rigid sheets, often used in construction and furniture making.
• fibrefill

  nounC1-C2 / Low-Frequency Specialist
  /ˈfaɪ.bə.fɪl/A synthetic, fibrous material used as a soft, insulating filler in products like pillows, quilts, and insulated clothing.
• fibreglass

  nounC1
  /ˈfaɪ.bə.ɡlɑːs/A material made from extremely fine strands of glass, used for insulation or to create strong, lightweight composite structures.
• fibrescope

  nounC1
  /ˈfaɪ.bə.skəʊp/A flexible instrument containing optical fibres, used for viewing internal parts of the body or inspecting machinery.
• fibril

  nounC1/C2
  /ˈfʌɪbrɪl/A very small or delicate fibre, especially one of the microscopic strands that make up a larger fibre, muscle, or nerve cell.
• fibrilla

  nounVery Low
  /fʌɪˈbrɪlə/A very small or fine fibre; a slender thread-like structure, especially in biological contexts.
• fibrillate

  verb-intransitiveverb-transitiveC1
  /ˈfʌɪbrɪleɪt/To make or undergo a rapid, irregular, and uncontrolled contraction of muscle fibers, especially the heart.
• fibrillation

  nounC1-C2 / Low-frequency technical
  /ˌfaɪ.brɪˈleɪ.ʃən/A rapid, irregular, and uncoordinated contraction of muscle fibres, most commonly referring to cardiac muscle (heart).
• fibrin

  nounC2
  /ˈfʌɪbrɪn/An insoluble protein formed during blood clotting, forming a mesh that traps platelets and blood cells.
• fibrinogen

  nounC2/Technical
  /fʌɪˈbrɪnədʒ(ə)n/A soluble plasma protein that is converted into fibrin during blood clotting.
• fibrinoid

  adjectivenounVery low
  /ˈfaɪ.brɪ.nɔɪd/A pathological material resembling fibrin, often found in diseased tissues.
• fibrinolysin

  nounC2
  /ˌfaɪ.brɪ.nəʊˈlaɪ.sɪn/A proteolytic enzyme that dissolves fibrin, a key protein in blood clots.
• fibrinolysis

  nounVery Low Frequency / C2
  /ˌfaɪ.brɪˈnɒl.ɪ.sɪs/The enzymatic breakdown of fibrin in blood clots.
• fibro-

  nounVery Low
  /ˈfaɪ.brəʊ/A combining form meaning 'fibre', 'fibrous tissue', or 'connective tissue'.
• fibroadenoma

  nounC2 (Highly specialized/Medical)
  /ˌfaɪ.brəʊ.æ.dəˈnəʊ.mə/A benign (non-cancerous) tumour consisting of glandular and connective tissue, commonly found in the breast.
• fibroblast

  nounVery low
  /ˈfaɪ.brə.blæst/A type of cell found in connective tissue that produces collagen and other fibres.

Showing 1481–1500 of 5868 words.