Something brought about by a cause or agent; a result. The power to produce an outcome or achieve a result; influence: The drug had an immediate effect on the pain. The government's action had no effect on the trade imbalance. A scientific law, hypothesis, or phenomenon: the photovoltaic effect. Advantage; avail: used her words to great effect in influencing the jury. The condition of being in full force or execution: a new regulation that goes into effect tomorrow. Something that produces a specific impression or supports a general design or intention: The lighting effects emphasized the harsh atmosphere of the drama. A particular impression: large windows that gave an effect of spaciousness. Production of a desired impression: spent lavishly on dinner just for effect. The basic or general meaning; import: He said he was greatly worried, or words to that effect. Movable belongings; goods. To bring into existence. To produce as a result. To bring about. See Usage Note at affect1. in effect In essence; to all purposes: testimony that in effect contradicted her earlier statement.