1. In Current Science, a particle that has an antisymmetric wave function, and hence half-integral spin, and can be described by Fermi–Dirac statistics. Cf. boson. A fermion is an elementary or composite particle, such as an electron, quark, or proton, whose spin is an integer multiple of 1/2. Fermions act on each other by exchanging bosons and are subject to the Pauli exclusion principle, which requires that no two fermions be in the same quantum state.

2. In Neu Theory, see fermionic, The fermions are:

- The matter particles – core [1a][1b], membrane [2a][2b], and the plasm [3a].
- The spin energy particles – the electric charge shells [6+][6-].