(informal) A covert or clandestine entry into a building etc. to obtain information for an intelligence operation.

plural of black bag operation

plural of floating-point operation

Alternative form of floating point operation

(theology) From the work worked; referring to sacraments deriving their power from Christ's work rather than the role of humans, and thus not requiring faith to be effective.

(rail transport) The operation of a train without a conductor or guard as a cost-cutting measure; one-man operation.

plural of suede-shoe operator

(slang) A flashy and dishonest trader.

(euphemistic) A military situation resembling a war (usually referencing the events of February 2022 in the Russo-Ukrainian War)

plural of bastard operator from hell