For the similar sounding local law, please see Ordinance.
Ordnance was a department aboard Starfleet starships.
Shortly after an away mission to the USS Glenn, the USS Discovery bridge inquired Ordnance if they had completed modifications on something. (DIS: "Context Is for Kings")
This was only heard mentioned in background chatter. The latter part of the communication was not audibly heard.
In 2268, Captain James T. Kirk asked Montgomery Scott to have Ordnance manufacture new phasers to replace those transformed into swords by the Beta XII-A entity. (TOS: "Day of the Dove")