Main Entry: neu·tron

Pronunciation: \ˈnü-ˌträn, ˈnyü-\

Function: noun

Etymology: probably from neutral

Date: 1932

: an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus

— neu·tron·ic \nü-ˈträ-nik, nyü-\ adjective