EFFECTIVE

[adjective]Something can be described as effective if it produces the results that it was intended to.It's a very effective cure for a headache.The lighting for the production made a very effective use of shadow.See also effective at effect (USE).A person can also be described as effective if they are skilled in a particular way.She's a very effective teacher.You can also use effective to mean in fact, although not officially.Although she's not officially our boss, she's in effective control of the office.