1) Antilepton 
(from the article `physical science, principles of`) ...nuclei have a higher-than-ideal ratio of protons to neutrons and may adjust the proportion by the reverse process, a proton being converted into a ... ...and antineutrons consist of antiquarks. Neutrinos too have spin 12 and therefore have corresponding antiparticles known as antin...
[n] - the antiparticle of a neutrino
noun the antiparticle of a neutrino
the antiparticle of a neutrino, distinguished from the neutrino by having clockwise rather than counterclockwise spin when observing in the direction of motion.