1. To perform a work or labour; to exert power or strengh, physical or mechanical; to act.
2. (Science: medicine) To produce an appropriate physical effect; to issue in the result designed by nature; especially, to take appropriate effect on the human system.
3. To act or produce effect on the mind; to exert moral power or influence. The virtues of private persons operate but on a few. (Atterbury) A plain, convincing reason operates on the mind both of a learned and ignorant hearer as long as they live. (swift)
4. (Science: surgery) 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.
5. To deal in stocks or any commodity with a view to speculative profits.
Origin: L. Operatus, p.p. Of operari to work, fr. Opus, operis, work, labour; akin to Skr. Apas, and also to G. Uben to exercise, OHG. Uoben, Icel. Fa. Cf. Inure, Manoeuvre, Ure.