Origin: 1300–50; (v.) Middle English rescuen < Old French rescourre, equivalent to re-re- + escourre to shake, drive out, remove < Latin excutere (ex-ex-1 + -cutere, combining form of quatere to shake); (noun) Middle English, derivative of the v.
c.1300 (n. and v.), from stem of O.Fr. rescourre, from re-, intensive prefix, + escourre "to cast off, discharge," from L. excutere "to shake off, drive away," from ex- "out" + -cutere, combining form of quatere "to shake" (see quash).