c.1400, "unusual behavior," also "singleness of aim or purpose," from Old French singulerte "peculiarity" (12c., Modern French singularité) or directly from Late Latin singularitatem (nominative singularitas) "a being alone," from singularis (see singular (adj.)). Meaning "fact of being different from others" is c.1500. Mathematical sense of "point at which a function takes an infinite value" is from 1893. Astronomical use is from 1965.
A point of infinite density and infinitesimal volume, at which space and time become infinitely distorted according to the theory of General Relativity. According to the big bang theory, a gravitational singularity existed at the beginning of the universe. Singularities are also believed to exist at the center of black holes.
Mathematics A point at which the derivative does not exist for a given function but every neighborhood of which contains points for which the derivative exists.