modus operandi

UK: /ˈməʊdəs ˌɒpəˈrændiː/

US: /ˈmoʊˌdəs ɑpəˈrændi, -daɪ/

US: (mō′dəs op′ə ran′dē, -dī; Lat. mō′do̅o̅s ō′pe rän′dē)

Inflections of 'modus operandi' (n): npl: modi operandi

WordReference Random House Learner's Dictionary of American English © 2025

mo•dus op•e•ran•di /ˈmoʊˌdəs ɑpəˈrændi, -daɪ/   n. [countable] pl. mo•di operandi /ˈmoʊdi ɑpəˈrændi, ˈmoʊdaɪ/.  

1. Foreign Terms method of working or operating:
   The burglars had a modus operandi that led the detectives to them.

See -mod-.

WordReference Random House Unabridged Dictionary of American English © 2025

mo•dus op•e•ran•di  (mō′dəs op′ə ran′dē, -dī; Lat. mō′do̅o̅s ō′pe rän′dē), pl. mo•di op•e•ran•di 

(mō′dē op′ə ran′dē, mō′dī op′ə ran′dī; Lat. mō′dē ō′pe rän′dē). 
1. Foreign Terms mode of operating or working.

• Latin modus operandī
• 1645–55

Collins Concise English Dictionary © HarperCollins Publishers::

modus operandi / ˈməʊdəs ˌɒpəˈrændiː -ˈrændaɪ/ noun ( modi operandi / ˈməʊdiː ˌɒpəˈrændiː ˈməʊdaɪ ˌɒpəˈrændaɪ/)

1. procedure; method of operating

Etymology: 17th Century: from Latin