- Babinski, Babinski reflex, Babinski sign - extension upward of the toes when the sole of the foot is stroked firmly on the outer side from the heel to the front; normal in infants under the age of two years but a sign of brain or spinal cord injury in older persons
--1 is a kind of reflex, instinctive reflex, innate reflex, inborn reflex, unconditioned reflex, physiological reaction