fraction (n.) Look up fraction at Dictionary.com
late 14c., originally in the mathematical sense, from Anglo-French fraccioun (Old French fraccion, 12c., "breaking") and directly from Late Latin fractionem (nominative fractio) "a breaking," especially into pieces, noun of action from past participle stem of Latin frangere "to break," from PIE root *bhreg- "to break" (cognates: Sanskrit (giri)-bhraj "breaking-forth (out of the mountains);" Gothic brikan, Old English brecan "to break;" Lithuanian brasketi "crash, crack;" Old Irish braigim "break" wind). Meaning "a breaking or dividing" is from early 15c.; sense of "broken off piece, fragment," is from c.1600.