Home›Browse›S›sympathetic nervesympathetic nerveOur editors are putting together more complete content — check back in about 20 minutessympathetic nervesympathetic nerve — nounnoun1. a nerve of the autonomic nervous system that prepares the body for action1.nounDefinitiona nerve of the autonomic nervous system that prepares the body for actionExampleThe sympathetic nerve accelerates the heart rate during stress.