# modus operandi

idiom · CEFR C1

Source: https://englishreference.com/idiom/modus-operandi
Updated: 2026-08-03

## Meaning

A person's characteristic way of doing something, recognisable across occasions.

## Examples

- Flattery first, then the request — that's his modus operandi.
- The two burglaries shared a modus operandi precise enough to link them in a single file.
- The firm's modus operandi was consistent across a decade of acquisitions: buy quietly, keep the founders on for eighteen months, and rename everything the week after they leave.

## Origin

Modus operandi is Latin for mode of operating, and the vocabulary is Roman — modus, a measure or manner, is one of the most heavily used nouns in Roman legal and philosophical writing. The phrase itself is a later Latin construction that English picked up in the seventeenth century for any settled method of working. Its modern career belongs to police work: as criminal investigation became systematic in the nineteenth century, detectives began filing offences by the way they were committed, on the assumption that the method is more consistent than the disguise. Officers abbreviated it to MO, and crime writers spread the abbreviation everywhere. In general English the phrase has kept the detective's implication. Describing someone's modus operandi suggests a pattern observed from outside, and often one they would rather not have had noticed.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.