n. & v.
n. 1 the result or consequence of an action etc. 2 efficacy (had little effect). 3 an impression produced on a spectator, hearer, etc. (lights had a pretty effect; my words had no effect). 4 (in pl.) property, luggage. 5 (in pl.) the lighting, sound, etc., used to accompany a play, film, broadcast, etc. 6 Physics a physical phenomenon, usually named after its discoverer (Doppler effect). 7 the state of being operative.
v.tr. 1 bring about; accomplish. 2 cause to exist or occur. bring (or carry) into effect accomplish. for effect to create an impression. give effect to make operative. in effect for practical purposes; in reality. take effect become operative. to the effect that the general substance or gist being. to that effect having that result or implication. with effect from coming into operation at or on (a stated time or day).
[ ME f. OF effect or L effectus (as EX-(1), facere make) ]