op·er·a·tion 
(ŏp′ə-rāshən)
(ŏp′ə-rāshən)n.
1. The act or process of operating or functioning.
2. The state of being operative or functional: a factory in operation.
3. A process or series of acts involved in a particular form of work: the operation of building a house.
4. An instance or method of efficient, productive activity: That restaurant is quite an operation.
5. An unethical or illegal business: a fencing operation for stolen goods.
6. Medicine A surgical procedure for remedying an injury, ailment, defect, or dysfunction.
7. Mathematics A process or action, such as addition, substitution, transposition, or differentiation, performed in a specified sequence and in accordance with specific rules.
8. A logical operation.
9. Computers An action resulting from a single instruction.
10.
a. A military or naval action, campaign, or mission.
b. operations The headquarters or center from which a military action, flights into and out of an airfield, or other activities are controlled.
11. operations The division of an organization that carries out the major planning and operating functions.