GOSMACS = G = gotcha

Gosperism /gos'p*r-izm/ n.

A hack, invention, or saying due to elder days arch-hacker R. William (Bill) Gosper. This notion merits its own term because there are so many of them. Many of the entries in HAKMEM are Gosperisms; see also life.

--The Jargon File version 4.3.1, ed. ESR, this entry manually entered by rootbeer277.