What is another word for M.O.?
Pronunciation: [ˌɛmˈə͡ʊ] (IPA) 
M.O. or modus operandi, refers to a person's method of operation, particularly when committing a crime. There are numerous synonyms for this phrase that can be used interchangeably. These include "mode of operation," "pattern of behavior," "style of behavior," and "system of operation." Other synonyms that can be used include "tactics," "strategy," "approach," "methodology," and "procedures." In essence, any phrase or word that describes the way a person goes about doing something could potentially be a synonym for M.O. As such, depending on the context and the speaker's preference, different synonym options might be more suitable than others.
