A room in a hospital used for performing surgery (originally designed for operations in front of observers).
A participant in an operation.
An employee or other worker with some particular function or skill.
A spy, secret agent, or detective.
Functional, in working order.
Effectual or important.
Having the power of acting; hence, exerting force, physical or moral; active in the production of effects.
Producing the appropriate or designed effect; efficacious.
Based upon, or consisting of, a surgical operation or operations.