What is singularity in Physics?

In Physics and Mathematics, singularity is defined as a point at which a complex function is undefined because it is neither differentiable nor single-valued while the function is defined in every neighbourhood of the point. Specifically, a quantity which approaches infinity as another parameter goes to zero. Like 1/x when x approaches zero. In astronomy, singularity is a hypothetical region in space in which gravitational forces cause matter to be infinitely compressed and space and time to become infinitely distorted.