/an'tee nooh"tron, -nyooh"-, an'tuy-/ , n. Physics.
1. an elementary particle having no charge and having a mass and spin equal to that of the neutron but with magnetic moment opposite to that of the neutron; the antiparticle of the neutron.
adj.
2. Also, anti-neutron . opposing the building, stockpiling, or use of neutron bombs: The antineutron lobby was outnumbered.
[ 1940-45; ANTI- + NEUTRON ]