/i fek"teuhr/ , n.
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.
[ 1595-1605; effec- var. s. of efficere (see EFFECT) + -tor -TOR ]