plural of multiplicative operation

plural of operating expense

(Canada) An illegal marijuana-growing operation, usually indoors.

plural of grow operation

Alternative form of operations research

plural of operating theatre

plural of operating room

In the work (already) cited or quoted. Used, typically in footnotes and endnotes, to cite in an abbreviated form a source that has been cited previously; frequently abbreviated as op. cit.

A covert operation typically involving activities that are highly clandestine and outside of standard military protocol.

plural of black operation