Definition: The term "decollimate" is a term used in the field of physics and astrophysics, specifically related to the motion of celestial bodies such as planets, moons, asteroids, and comets. The term refers to the process by which a body moves away from its orbit due to the gravitational attraction of other objects. When a celestial body decollimates, it is said to be in an elliptical or circular orbit around another object. This movement can occur due to various factors such as