minister (v.)
early 14c., "to perform religious rites, provide religious services;" mid-14c., "to serve (food or drink);" late 14c. "render service or aid," from Old French menistrer "to serve, be of service, administer, attend, wait on," and directly from Latin ministrare "to serve, attend, wait upon" (see minister (n.)). Related: Ministered; ministering.
minister (n.)
c.1300, "one who acts upon the authority of another," from Old French menistre "servant, valet, member of a household staff, administrator, musician, minstrel" (12c.), from Latin minister (genitive ministri) "inferior, servant, priest's assistant" (in Medieval Latin, "priest"), from minus, minor "less," hence "subordinate," (see minus) + comparative suffix *-teros. Formed on model of magister. Meaning "priest" is attested in English from early 14c. Political sense of "high officer of the state" is attested from 1620s, from notion of "service to the crown."