Definition of proton noun from the Oxford Advanced Learner's Dictionary



BrE BrE//ˈprəʊtɒn//
; NAmE NAmE//ˈproʊtɑːn//
(physics) Molecules and matter
jump to other results
a very small piece of matter (= a substance) with a positive electric charge that forms part of the nucleus (= central part) of an atom see also electron, neutron Wordfinderantiparticle, atom, electron, ion, neutron, nucleus, particle, positron, proton, valency See related entries: Molecules and matter Word Origin1920s: from Greek, neuter of prōtos ‘first’.
See the Oxford Advanced American Dictionary entry: proton