1.a business especially one run on a large scale;
a large-scale farming operation
2.a planned activity involving many people performing various actions;
they organized a rescue operation
3.a process or series of acts especially of a practical or mechanical nature involved in a particular form of work;
the operations in building a house
4.the state of being in effect or being operative;
that rule is no longer in operation
5.a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body;
they will schedule the operation as soon as an operating room is available
6.activity by a military or naval force (as a maneuver or campaign);
it was a joint operation of the navy and air force
7.(computer science) data processing in which the result is completely specified by a rule (especially the processing that results from a single instruction);
it can perform millions of operations per second
8.process or manner of functioning or operating;
the power of its engine determine its operation
9.(mathematics) calculation by mathematical methods;
the problems at the end of the chapter demonstrated the mathematical processes involved in the derivation
10. (psychology) the performance of some composite cognitive activity; an operation that affects mental contents;
the process of thinking
11. the activity of operating something (a machine or business etc.);
her smooth operation of the vehicle gave us a surprisingly comfortable ride