Pronunciation: (i-fek'tur), [key]
1. Also,effecter.a person or thing that effects.
2. Physiol.an organ or cell that carries out a response to a nerve impulse.
3. Biochem.a substance, as a hormone, that increases or decreases the activity of an enzyme.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.