Antonym: ineffective. Similar words: effectively, effectiveness, effect, in effect, take effect, affection, the greenhouse effect, affectionate. Meaning: [-tɪv] 
adj. 1. producing or capable of producing an intended result or having a striking effect 2. able to accomplish a purpose; functioning effectively 3. works well as a means or remedy 4. exerting force or influence 5. existing in fact; not theoretical; real 6. ready for service.
adj. 1. producing or capable of producing an intended result or having a striking effect 2. able to accomplish a purpose; functioning effectively 3. works well as a means or remedy 4. exerting force or influence 5. existing in fact; not theoretical; real 6. ready for service. 
Random good picture Not show
1. We find advertising on the radio very effective.
2. Television is an effective means of communication.
3. Antibiotics is effective to cure throat infection.
4. The drug is effective against a range of bacteria.
5. The law is no longer effective.
6. It has been demonstrated that this drug is effective.
7. They mounted an effective opposition to the bill.
8. This is an effective medium.
9. Minority groups need more effective parliamentary representation.
10. This has proved an effective preventive.
11. Is that new plan effective?
12. This car polish is an effective shield against rust.
13. Which method is the most effective?
14. Aspirin is a simple but highly effective treatment.
15. Commercial television is an effective medium for advertising.
16. The medicine is an effective cure for a headache.
17. Long prison sentences can be a very effective deterrent for offenders.
18. The company has done some effective marketing of the new model.
19. Water is not an effective shield against the sun's more harmful rays.
20. We have taken effective measures to preserve our natural resources.
21. The cheaper drugs are just as effective in treating arthritis.
22. The human race has one really effective weapon,[Sentence dictionary] and that is laughter. Mark Twain 
23. The article raised doubts about how effective the new drug really was.
24. If the law is to be effective it must be applied equitably.
25. I admire the effective use of colour in her paintings.
26. Preliminary results show that the vaccine is effective, but this has to be confirmed by further medical trials.
27. These are effective measures.
28. Discussion can be more effective than the use of brute force.
29. Poetry is simply the most beautiful, impressive and widely effective mode of saying things, and hence its importance.
30. A poet is one who can convert ordinary words into a meaningful and effective piece of writing.
More similar words: effectively, effectiveness, effect, in effect, take effect, affection, the greenhouse effect, affectionate, detective, objective, subjective, perspective, protective, collective, collectively, irrespective, respectively, retrospective, irrespective of, affect, affectation, infection, active, actively, deductive, addictive, proactive, productive, afflictive, hyperactive.