fermiumPronunciation: /ˈfəːmɪəm/Definition of fermium noun [mass noun] the chemical element of atomic number 100, a radioactive metal of the actinide series. Fermium does not occur naturally and was discovered in 1953 in the debris of the first hydrogen bomb explosion. (Symbol: Fm)Origin: 1950s: from the name of Fermi, Enrico + -iumfermium in other Oxford dictionaries Definition of fermium in the US English dictionary
