From Longman Dictionary of Contemporary Englisheffectiveef‧fec‧tive /ɪˈfektɪv/ ●●● S2 W1 adjective 1 EFFECTIVEsuccessful, and working in the way that was intended OPP ineffective The cheaper drugs are just as effective in treating arthritis. the painting’s highly effective use of colour Training is often much less effective than expected. the most effective ways of reducing inner city congestion► see thesaurus at successfulRegisterIn everyday English, people usually say that something works (well), rather than say that it is effective:The cheaper drugs work just as well.2 [no comparative, not before noun]SCLSTART TO HAPPEN, EXIST ETC if a law, agreement, or system becomes effective, it officially startseffective from The cut in interest rates is effective from Monday.3 [no comparative, only before noun]IN FACT real rather than what is officially intended or generally believed The rebels are in effective control of the city. —effectiveness noun [uncountable]COLLOCATIONSadverbsextremely/highly effectiveThe company launched a highly effective advertising campaign.nounsan effective wayWhat’s the most effective way to control crime?an effective methodExams are not the most effective method of assessing students’ abilities.an effective meansIs reducing the speed limit an effective means of reducing accidents?effective actionThe police must take effective action to protect the public.an effective solutionThe most effective solution to traffic congestion is to build more roads.an effective treatmentAntibiotics are still the most effective treatment for this disease.an effective systemThe country has a simple but effective welfare system.
Examples from the Corpuseffective• The advertisement was simple but remarkably effective.• As existing dominant males age so doubtless can the collaborative attacks of younger animals prove increasingly effective.• Capital prosecutions are hideously expensive; life imprisonment is cheaper and just as effective.• Provided that post-storage image processing is not a major priority, analogue technology is effective.• Malarone is a new drug that has already proved highly effective.• Penicillin can be taken in various forms and is effective against a wide range of infections.• His resignation is effective April 8.• How effective are lawyers in solving legal problems?• Pimozide is now also being used; it appears to be approximately as effective as haloperidol and may have fewer side effects.• Antibiotics are only effective if you finish the whole course of treatment.• In my opinion neither of these arguments is effective in destroying its opponent.• Doctors soon realized that this drug was also effective in relieving the symptoms of arthritis.• The less expensive drugs were just as effective in treating arthritis.• What we need is a tough and effective leader with a sense of direction.• Rapid advancements in technology have reduced the effective lifespans of computers.• Our training programme covers a range of effective management techniques.• The idea that there could be such authority without effective power hardly occurred to anyone.• An effective teacher will always produce better exam results.• High-performance work design enabled them to achieve those objectives by increasing flexibility, output quality and effective use of assets.• The effective use of color can make a small room look much bigger.• The new system has proved to be a highly effective way of extending trading hours.• There are many effective ways of using videos in language teaching.highly effective• Despite this opposition the attack was highly effective.• It is well targeted and highly effective.• We need spies because Soviet security is highly effective.• Malarone has already proved highly effective in other trials.• Gold salts are highly effective in the management of patients with rheumatoid arthritis, most adverse reactions being mild and reversible.• As a political strategy it was highly effective, successfully confronting the medical discourse which lay behind regulation.• Hepatitis remains a killer, and although a highly effective vaccine is now available, very few gay men have taken it.• This drug is highly effective when used within the first several hours after the onset of acute arthritis.From Longman Business Dictionaryeffectiveef‧fec‧tive /ɪˈfektɪv/ adjective1working well and producing the result or effect that was wanted or intendedThe company mounted a very effective publicity campaign.The 7% increase in sales shows that the company has become more effective in marketing its services. → see also cost-effective2[not before a noun] if a law, agreement, or system becomes effective, it officially startseffective fromThe new rates are effective from 22 February.3[only before a noun] real, although not obvious or officially recognizedFollowing the takeover, they now have effective control of the German computer market.