A gravitino is a theoretical particle in physics that is associated with the force of gravity. It is a type of supersymmetric particle, which means it is predicted to exist in theories that extend the Standard Model of particle physics. Gravitinos are considered the superpartners of gravitons, the particles that mediate gravitational interactions. In supersymmetry, every known particle has a corresponding superpartner with different spin properties. The existence of gravitinos could help explain certain phenomena in cosmology and particle physics, such as dark matter. However, as of now, gravitinos have not been observed experimentally, and their properties remain largely theoretical.