n(y)ü.ˈtrē(ˌ)nō noun
( -s )
Etymology: Italian, from neutrone neutron (probably from English neutron ) + -ino (diminutive suffix)
: an uncharged elementary particle that comes in two forms associated respectively with the electron and the muon, that is a lepton with one-half quantum unit of spin and is believed to be massless, and that interacts very weakly with matter after its creation in the process of particle decay