diffraction (n.)

in optics, "the spreading of light or deflection of its rays," 1670s, from French diffraction (17c.) or directly from Modern Latin diffractionem (nominative diffractio), noun of action from past-participle stem of Latin diffringere "break apart in pieces," from dis- "apart" (see dis-) + frangere "to break" (from PIE root *bhreg- "to break").