operation

noun

1. (uncountable)The method by which a device performs its function.

   “It is dangerous to look at the beam of a laser while it is in operation.”

2. (uncountable)The method or practice by which actions are done.
3. (uncountable)The act or process of operating (verb): agency; the exertion of power, physical, mechanical, or moral.

   “the pain and sickness caused by manna are confessedly nothing but the effects of its operations on the stomach and guts.”

   “Speculative painting, without the assistance of manual operation, can never attain to perfection.”

4. (countable)A planned undertaking.

   “The police ran an operation to get vagrants off the streets.”

   “The Katrina relief operation was considered botched.”

5. (countable)A business or organization.

   “We run our operation from a storefront.”

   “They run a multinational produce-supply operation.”

6. (countable)A surgical procedure.

   “She had an operation to remove her appendix.”

   “This done, ſhe performs the very ſame Operation on the other Side of the Cock's Body, and there takes out the other Stone; then ſhe ſtitches up the Wounds, and lets the Fowl go about as at other Times, till the Capon is fatted in a Coup, which is commonly done from Chriſtmas to Candlemas, and after.”

7. (countable)A procedure for generating a value from one or more other values (the operands).

   “The number of operands associated with an operation is called its arity; an operation of arity 2 is called a binary operation.”

8. (countable)A procedure for generating a value from one or more other values (the operands).
9. (countable)A military campaign (e.g. Operation Desert Storm).
10. (countable, obsolete)Effect produced; influence.

    “The bards […] had great operation on the vulgar.”