[op.er.ate] vb -at.ed ; -at.ing [L operatus, pp. of operari to work, fr. oper-, opus work; akin to OE efnan to perform, Skt apas work] vi (1588) 1: to perform a function: exert power or influence "factors operating against our success"
2: to produce an appropriate effect "the drug operated quickly" 3 a: to perform an operation or a series of operations b: to perform surgery c: to carry on a military or naval action or mission
4: to follow a course of conduct that is often irregular "crooked gamblers operating in the club" ~ vt 1: bring about, effect
2. a: to cause to function: work b: to put or keep in operation
3: to perform an operation on; esp: to perform surgery on