effective

exerting force or influence

“the law is effective immediately”

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”

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...”

existing in fact; not theoretical; real

“a decline in the effective demand”

ready for service

“the fort was held by about 100 effective soldiers”

works well as a means or remedy

“an effective reprimand”