ordinance (n.) Look up ordinance at Dictionary.com
c.1300, "an authoritative direction, decree, or command" (narrower or more transitory than a law), from Old French ordenance (Modern French ordonnance) or directly from Medieval Latin ordinantia, from Latin ordinantem (nominative ordinans), present participle of ordinare "put in order" (see ordain). By early 14c. senses had emerged of "arrangement in ranks or rows" (especially in order of battle), also "warlike provisions, equipment" (a sense now in ordnance).