refraction Look up refraction at Dictionary.com
1578, from L.L. refractionem (nom. refractio) "a breaking up," from L. refractus, pp. of refringere "to break up," from re- "back" + comb. form of frangere "to break" (see fraction). Refractory "stubborn, obstinate, perverse" is attested from 1613 (earlier refractorious, 1555), from L. refractarius "obstinate." Refrangible first recorded 1673.