1. a secondary effect or byproduct that occurs alongside a primary phenomenon but does not causally influence it
Usage: often used in philosophy and science to describe events that accompany but do not cause other events
2. in philosophy of mind, a mental state or conscious experience that is caused by physical processes but does not itself cause any physical effects
Usage: technical term in philosophy and cognitive science

Examples

• Some philosophers argue that consciousness is merely an epiphenomenon of brain activity.
• The company's increased productivity was an epiphenomenon of the new management structure, not its cause.
• In the debate over free will, epiphenomenalism suggests that our conscious choices are epiphenomena of neural processes.
• The fever is an epiphenomenon of the infection, accompanying it but not causing the underlying disease.
• Critics claim that the theory treats human agency as an epiphenomenon rather than a genuine causal force.