fraction Look up fraction at Dictionary.com
late 14c., from L.L. fractionem (nom. fractio) "a breaking," especially into pieces, from root of L. frangere (pt. fregi) "to break," from PIE base *bhr(e)g- (cf. Skt. (giri)-bhraj "breaking-forth (out of the mountains);" Goth. brikan, O.E. brecan "to break;" Lith. brasketi "crash, crack;" O.Ir. braigim "break" wind). Mathematical sense was the original one in English. Sense of "broken off piece, fragment," is from c.1600.