ˌɒpəˈɹeɪʃən ˌɑpəˈɹeɪʃən pəɹ.ˈfɔɹ.məns pɹəˈsiːdʒə pɹəˈsidʒɚ ˈpɹəʊsɛs ˈsɝdʒəɹi ˈsɜːdʒəɹi the activity of operating something (a machine or business etc.) her smooth operation of the vehicle gave us a surprisingly comfortable ride a planned activity involving many people performing various actions they organized a rescue operation the biggest police operation in French history running a restaurant is quite an operation consolidate the companies various operations 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 certain machine tool operations 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 he died while undergoing surgery (mathematics) calculation by mathematical methods the problems at the end of the chapter demonstrated the mathematical processes involved in the derivation they were learning the basic operations of arithmetic activity by a military or naval force (as a maneuver or campaign) it was a joint operation of the navy and air force a business especially one run on a large scale a large-scale farming operation a multinational operation they paid taxes on every stage of the operation they had to consolidate their operations (psychology) the performance of some composite cognitive activity; an operation that affects mental contents the process of thinking the cognitive operation of remembering (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 process or manner of functioning or operating the power of its engine determines its operation the plane's operation in high winds they compared the cooking performance of each oven the jet's performance conformed to high standards the state of being in effect or being operative that rule is no longer in operation