Dictionary

To perform a work or labour; to exert power or strength, physical or mechanical; to act.

To produce an appropriate physical effect; to issue in the result designed by nature; especially to take appropriate effect on the human system.

To act or produce effect on the mind; to exert moral power or influence.

To perform some manual act upon a human body in a methodical manner, and usually with instruments, with a view to restore soundness or health, as in amputation, lithotomy, etc.

In operation; that operates.

Example: Don't touch the operating machinery.

Involved in an operation.