Ordinance vs. Ordnance
“Ordinance” usually refers to an official law, rule, or order. “Ordnance” refers to military weapons, ammunition, or related material. The spellings are close, but the meanings are unrelated.
Use “ordinance” for an official rule or law; use “ordnance” for military weapons, ammunition, or related supplies.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| official rule, regulation, or law made by an authority | ordinance | Use “ordinance.” |
| military weapons, ammunition, or related materiel | ordnance | Use “ordnance.” |
| word chosen only by sound/spelling similarity | meaning test required | The words are near-spellings but not interchangeable. |
Quick tests
Meaning / construction test
Does the sentence refer to an official rule or law?
If yes: Use “ordinance.”
If no: If it refers to military weapons, ammunition, or related supplies, use “ordnance.”
Caveat: These are different words, not regional spellings. Choose by meaning; specialist military uses of “ordnance” can be broader than a single weapon type.
Examples
The council adopted a new parking ordinance.
“Ordinance” means an official rule or law.
The depot stores military ordnance.
“Ordnance” refers to weapons, ammunition, or related military supplies.
The ordinance takes effect next month.
The legal/rule meaning selects “ordinance.”
Further guidance
Core difference
An ordinance is a law, rule, or official order; ordnance is military weaponry or associated supplies.
Usage Boundary
In legal or local-government prose, “ordinance” is the likely word; in military logistics or weapons contexts, “ordnance” may be intended.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- ordinance — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Meaning of ordinance as an official law, rule, or order
- ordnance — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Meaning of ordnance as military weapons, ammunition, and related supplies