effector

ef·fec·tor

noun \i-ˈfek-tər, -ˌtȯ(ə)r\

Definition of EFFECTOR

1

: a bodily organ (as a gland or muscle) that becomes active in response to stimulation

2

: a molecule (as an inducer, a corepressor, or an enzyme) that activates, controls, or inactivates a process or action (as protein synthesis or the release of a second messenger)