op·er·ate / ˈäpəˌrāt/ • v. 1. [tr.] (of a person) control the functioning of (a machine, process, or system): a shortage of workers to operate new machines. ∎  [intr.] (of a machine, process, or system) function in a specified manner: market forces were allowed to operate freely. ∎  [intr.] be in effect: there is a powerful law that operates in politics. ∎  (of a person or organization) manage and run (a business): many foreign companies operate factories in the U.S. ∎  [intr.] (of an organization) be managed and run in a specified way: neither company had operated within the terms of its charter. ∎  [intr.] (of an armed force) conduct military activities in a specified area or from a specified base: the mountain bases from which the guerrillas were operating.2. [intr.] perform a surgical operation: the surgeons refused to operate my brother had to be operated on last week.3. [intr.] function; work: we have as yet no conclusive evidence on how these cells operate.

operate †produce an effect; effect, produce, bring about XVII; (orig. U.S.) cause or direct the working of XIX. f. operāt-, pp. stem of L. operārī work, bestow labour upon, f. oper-, OPUS; see -ATE3.
So operation working, performance XIV; surgical act XVI; (mil., math.) XVIII. — (O)F. — L. operative XVI; sb. worker XIX. — late L. operator XVI. — late L.