v.
    - (with reference to a machine, process, etc.) function or control the functioning of:![]()  market forces were allowed to operate freely. 
- (with reference to an organization) manage or be managed and run. ▸(of an armed force) conduct military activities. 
- be in effect.
- perform a surgical operation.
Etymology
  C17: from L. operat-, operari, from opus, oper- ‘work’.