Definition: Antecurvature is a term in physics related to the bending of light or other particles due to a curvature in spacetime, which can lead to deviations from Newtonian physics. This concept was first introduced by Albert Einstein and later explored by other physicists such as Robert Millikan and Richard Feynman, who further developed it into quantum mechanics. It's an essential aspect of General Relativity, the theory that explains gravity at its most fundamental level.