"one who or that which enables another," in any sense, 1610s, agent noun from enable.
Entries linking to enabler
enable v.
early 15c., "to make fit;" mid-15c., "to make able to," from en- (1) "make, put in" + able. Related: Enabled; enabling. An enabling act (1684) is so called because it empowers a body or person to take certain action.