·noun Effect produced; influence.
II. Operation ·noun The method of working; mode of action.
III. Operation ·noun The act or process of operating; agency; the exertion of power, physical, mechanical, or moral.
IV. Operation ·noun Something to be done; some transformation to be made upon quantities, the transformation being indicated either by rules or symbols.
V. Operation ·noun That which is operated or accomplished; an effect brought about in accordance with a definite plan; as, military or naval operations.
VI. Operation ·noun Any methodical action of the hand, or of the hand with instruments, on the human body, to produce a curative or remedial effect, as in amputation, ·etc.