Definition of "Effective" :

adjective: existing in fact; not theoretical; real

"A decline in the effective demand."

adjective: able to accomplish a purpose; functioning effectively

"People who will do nothing unless they get something out of it for themselves are often highly effective persons...."

adjective: exerting force or influence

"The law is effective immediately."

adjective: producing or capable of producing an intended result or having a striking effect

"An air-cooled motor was more effective than a witch's broomstick for rapid long-distance transportation."

adjective: works well as a means or remedy

"An effective reprimand."

adjective: ready for service

"The fort was held by about 100 effective soldiers."