Origin: 1350–1400; Middle English commissarie (< Anglo-French ) < Medieval Latin commissārius, equivalent to Latin commiss(us) (past participle of committere to commit) + -ārius-ary
mid-14c., "one to whom special duty is entrusted by a higher power," from M.L. commissarius, from L. commissus "entrusted," pp. of committere (see commit). Originally ecclesiastical, the military sense of "official in charge of supply of food, stores, transport" dates to late 15c.