Dictionary.com
definitions

startle reflex

n.
  1. The reflex response of an infant in which the limb and neck muscles contract when the infant is allowed to drop a short distance or is startled by a sudden noise or jolt.Moro's reflex parachute reflex
  2. cochleopalpebral reflex
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.