Fermion and Heavy particle

Fermion noun - Any particle that obeys Fermi-Dirac statistics and is subject to the Pauli exclusion principle.

Heavy particle and fermion are semantically related. In some cases you can replace phrase "Heavy particle" with "Fermion", this terms are similar.

Heavy particle noun - Any of the elementary particles having a mass equal to or greater than that of a proton and that participate in strong interactions; a hadron with a baryon number of +1.

Fermion and heavy particle are semantically related. You can use "Fermion" instead a noun phrase "Heavy particle".