femtometre

/ˈfɛmtoʊˌmiːtər/
noun
  1. British spelling of 'femtometer'; a unit of length equal to one quadrillionth of a meter (10⁻¹⁵ meters).
    • A femtometre is also called a fermi in nuclear physics.
    • The nucleus of a carbon atom measures a few femtometres across.
    • In British scientific journals, they often write 'femtometre' instead of 'femtometer'.
Synonyms
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