disparity (n.)

1550s, "state or character of being essentially different;" 1590s, "quality of being unequal in rank, condition, etc.;" from Middle French disparité (16c.), from Medieval Latin disparitatem (nominative disparitas) "inequality," from dis- "not" (see dis-) + paritas "parity," from Latin adjective par (genitive paris) "equal" (see par (n.)). Related: Disparities.