early 13c., singularite, "unusual or exceptional behavior;" mid-14c as "singleness of aim or purpose, devotion to a single thing;" late 14c. as "individual or particular things," from Old French singulerte "peculiarity" (12c., Modern French singularité) and directly from Late Latin singularitatem (nominative singularitas) "a being alone," from singularis "single, solitary, one by one, one at a time; peculiar, remarkable," from singulus "one, one to each, individual, separate" (see single (adj.)).
The meaning "fact of being different from others" is attested from c. 1500. The mathematical sense of "point at which a function takes an infinite value" is from 1893. Astrophysics sense, "point of space where the density of matter or the curvature of space-time becomes infinite" (as in a black hole), is attested from 1965.
"having a single set of unpaired chromosomes," 1908, from German haploid (Strasburger, 1905), from Greek haploos "single, simple" (see haplo-) + -oid.
1660s, "painting or drawing done in different tints of a single color," from Latinized form of Greek monokhrōmos, also monokhrōmatos, "of a single color," from monos "single, alone" (from PIE root *men- (4) "small, isolated") + khrōma (genitive khrōmatos) "color, complexion, skin" (see chroma). As an adjective from 1849. Photographic sense is recorded from 1940.
"monument consisting of a single large block of stone," 1829, from French monolithe (16c.), from Latin monolithus (adj.) "consisting of a single stone," from Greek monolithos "made of one stone," from monos "single, alone" (from PIE root *men- (4) "small, isolated") + lithos "stone" (see litho-). Transferred and figurative use in reference to a thing or person noted for indivisible unity is from 1934.