What are superpartners of particles?

In particle physics, a superpartner (also sparticle) is a hypothetical elementary particle. Supersymmetry is one of the synergistic bleeding-edge theories in current high-energy physics which predicts the existence of these “shadow” particles. The word superpartner is a portmanteau of the words supersymmetry and partner (sparticle is a portmanteau of supersymmetry and particle).