Getting confused with words that look almost exactly alike is nothing new, and this is the case with the terms ordinance and ordnance which are separated by a single extra letter “i” in one of them. Despite their similarity in appearance, these words are worlds apart in terms of their meanings. Today, we will differentiate them and establish how they should be used in your writing.
The term ordinance is used as a noun referring to “an authoritative decree or direction” or “a law set forth by a governmental authority, specifically, a municipal regulation.”
Bremen Approves Change in Fiscal Year, Elects Thorpe, Rejects Land Use Ordinance
The Lincoln Country NewsAfter residents complain, New Lenox to modify zoning ordinance for gun shops
The Herald-News
On the other hand, the word ordnance is also used as a noun which refers to “military supplies including weapons, ammunition, combat vehicles, and maintenance tools and equipment.”
Hong Kong’s ticking time bomb: unexploded wartime ordnance
South China Morning PostUnexploded ordnance missing from Milford-on-Sea
ITV News
It may also be used to refer to “a branch of the armed forces dealing with the supply and storage of weapons, ammunition, and related equipment.”
American Ordnance Pays Former Workers after Violating Americans with Disability Act
EHS TodayGeneral Dynamics, U.S. Ordnance share U.S. Army contract for M2 machine guns
UPI.com
To help you remember their difference, you may use this simple trick. Remember that if you are referring to municipal regulation, you should choose ordinance, which has the extra “i” because following regulations requires extra effort. For military supplies and equipment, use ordnance which has one less letter because peace requires less weapons.