modus operandi

American  

[moh-duhs op-uh-ran-dee, -dahy, moh-doos oh-pe-rahn-dee] / ˈmoʊ dəs ˌɒp əˈræn di, -daɪ, ˈmoʊ dus ˌoʊ pɛˈrɑn di /

noun

plural

modi operandi

1. a mode of operating or working.

   The aim of a scientist is to investigate the modus operandi of the natural world.

2. one’s usual way of doing something: MO

   A criminal’s modus operandi can give the police a lead.

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modus operandi British  

/ -ˈrændaɪ, ˈməʊdəs ˌɒpəˈrændiː /

noun

1. procedure; method of operating

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modus operandi Cultural  

1. The way someone does something; a characteristic method: “Her modus operandi in buying a new car always included a month of research.” This phrase, often abbreviated “m.o.,” is used by police to describe a criminal's characteristic way of committing a crime. From Latin, meaning “method of operation.”

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Etymology

Origin of modus operandi

First recorded in 1645–55; New Latin: literally “mode of working”

Example Sentences

McLelland, who founded the National Association of Player Welfare Officers, said she believed "mandated areas of responsibility and a prescribed modus operandi should be put in place in each and every club".

From BBC • Mar. 29, 2026

Other digital asset treasury companies that sought to ape Saylor’s modus operandi have suffered a similar fate.

From MarketWatch • Feb. 5, 2026

Three former case managers, who worked as liaisons between clients and attorneys, described the same modus operandi at DTLA: Sign up personal injury clients, then get them to agree to surgeries.

From Los Angeles Times • Dec. 31, 2025

His modus operandi generally is better understood when he is so considered.

From The Wall Street Journal • Dec. 18, 2025

Except when I glance at him, I see that his face has bricked up and I can tell running away is not part of his modus operandi.

From "I'll Give You the Sun" by Jandy Nelson

Related Words

• rule of thumb