operation

1 :  performance of a practical work or of something involving the practical application of principles or processes Practice until you can go through the whole operation without hesitation or thinking.

2a :  an exertion of power or influence the operation of a drugb :  the quality or state of being functional or operative The plant is now in operation.c :  a method or manner of functioning a machine of very simple operation

3 :  efficacy, potency —archaic except in legal usage

4 :  a procedure performed on a living body usually with instruments especially for the repair of damage or defect or the restoration of health needed an operation to remove his appendix

5 :  any of various mathematical or logical processes (such as addition) of deriving one entity from others according to a rule Multiplication is one mathematical operation.

6a :  a usually military action, mission, or maneuver including its planning and execution military operations for a large-scale invasionb operations plural :  the office on the flight line of an airfield where pilots file clearance for flights and where flying from the field is controlledc operations plural :  the agency of an organization charged with carrying on the principal planning and operating functions of a headquarters and its subordinate units

7 :  a business transaction especially when speculative continued his operations in cotton futures

8 :  a single step performed by a computer in the execution of a program (see ¹program 6b)