1250-1300; (v.) Middle Englishsucuren < Old Frenchsuc(c)urre, socorre < Latinsuccurrere to go beneath, run to help, equivalent to suc-suc- + currere to run (see current); (noun) Middle Englishsoc(o)ur, back formation from sucurs (taken as plural) < Old French < Medieval Latinsuccursus, equivalent to Latinsuccur(rere) + -sus, var of -tus suffix of v. action
early 13c., from Anglo-Fr. succors "help, aid," O.Fr. sucurres, from M.L. succursus "help, assistance," from pp. of L. succurrere "run to help," from sub "up to" + currere "to run" (see current). Final -s mistaken as a plural inflexion and dropped late 13c.