v. t. [ L. opacatus, p. p. of opacare. ] To darken; to cloud. [ Obs. ] Boyle. [ 1913 Webster ]

v. t. 1. To produce, as an effect; to cause. [ 1913 Webster ]

The same cause would operate a diminution of the value of stock. A. Hamilton. [ 1913 Webster ]

2. To put into, or to continue in, operation or activity; to work; as, to operate a machine. [ 1913 Webster ]

v. i. [ imp. & p. p. Operated p. pr. & vb. n. Operating. ] [ L. operatus, p. p. of operari to work, fr. opus, operis, work, labor; akin to Skr. apas, and also to G. üben to exercise, OHG. uoben, Icel. æfa. Cf. Inure, Maneuver, Ure. ] 1. To perform a work or labor; to exert power or strength, physical or mechanical; to act. [ 1913 Webster ]

2. To produce an appropriate physical effect; to issue in the result designed by nature; especially (Med.), to take appropriate effect on the human system. [ 1913 Webster ]

3. To act or produce effect on the mind; to exert moral power or influence. [ 1913 Webster ]

The virtues of private persons operate but on a few. Atterbury. [ 1913 Webster ]

A plain, convincing reason operates on the mind both of a learned and ignorant hearer as long as they live. Swift. [ 1913 Webster ]

4. (Surg.) 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. [ 1913 Webster ]

5. To deal in stocks or any commodity with a view to speculative profits. [ Brokers' Cant ] [ 1913 Webster ]