B1[C or U]the result of a particular influence: The radiation leak has had a disastrous effect on/upon the environment.I tried taking tablets for the headache but they didn't have any effect.I think I'm suffering from the effects of too little sleep.She has a lot of confidence which she uses to good effect (= to her advantage) in interviews.→ See alsoaftereffectsOutcomes and consequencestake effectC1to produce or achieve the results you want: They had to wait ten minutes for the anaesthetic to take effect before they stitched up the cut.Outcomes and consequencesfor effect›If you say or do something for effect, you intentionally do it to shock people or attract their attention: I get the impression that she uses bad language in meetings for effect.Making people sad, shocked and upsetin effectC2in fact, or in practice: So in effect the government have lowered taxes for the rich and raised them for the poor.True, real, false, and unrealto that effect(alsoto the effect that)›used to express that what you are reporting is only a short and general form of what was really said: She said she was unhappy, or words to that effect.He said something to the effect that he would have to change jobs if the situation continued.Approximate