1) Reflected heat, light, or color;

2) A mirrored image.

3) An automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to the spinal cord and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness and often without passing to the brain (the knee-jerk reflex);

4) The process that culminates in a reflex and comprises reception, transmission, and reaction;

4) reflexes plural: the power of acting or responding with adequate speed.