fermiPronunciation: /ˈfəːmi/Definition of fermi noun (plural same) a unit of length equal to 10−15 metre (one femtometre), used in nuclear physics. It is similar to the diameter of a proton. Origin: early 20th century: named after E. Fermi (see Fermi, Enrico)fermi in other Oxford dictionaries Definition of fermi in the US English dictionary
