Ordinance or Ordnance?

The Quick Answer
What is the difference between ordinance and ordnance?

Ordinance is a noun denoting an authoritative rule or regulation.
  • Slavery was abolished by a royal ordinance in 1897.
Ordnance is a mass noun referring to military materiel or artillery.
  • Do not touch any military ordnance that may be found lying around this area.

Ordinance

The noun ordinance is an authoritative order or regulation.

Examples:
  • No law or ordinance is mightier than understanding. (Plato)
  • Law: an ordinance of reason for the common good, made by him who has care of the community. (Thomas Aquinas)

Ordnance

The mass noun ordnance refers to military materiel (e.g., weapons, ammunition, fuel).

Examples:
  • The guns are a new and impressive addition of ordnance.
  • Military aircrafts can be used to carry a wide variety of ordnance.

See Also

adverse or averse? affect or effect? appraise or apprise? avenge or revenge? bare or bear? complement or compliment? dependant or dependent? discreet or discrete? disinterested or uninterested? e.g. or i.e.? envy or jealousy? imply or infer? its or it's? material or materiel? poisonous or venomous? practice or practise? principal or principle? tenant or tenet? who's or whose?
What are nouns? What are mass nouns? The difference between materiel and material List of easily confused words