-ˌäpəˈrandē, -ˌdī noun
( plural modi operandi )
Etymology: New Latin
1. : a manner of operating or working
their modus operandi is the old Indian art of tracking — Frank Cameron
the modus operandi of a particularly nasty type of middle-class woman — John Nerber
2. : a distinct pattern or method of procedure thought to be characteristic of an individual criminal and habitually followed by him
got her picture identified, discovered her modus operandi, and put a stakeout on her neighborhood — Time
— abbr. M.O.