1. Definition
Pain (from Latin poena via Old French peine; German Schmerz from OHG smerza/smerzo and MHG smerze/smerz; Greek álgos; Latin dolor, acerbitas) is a complex sensory perception; as an acute event, it serves as a warning sign and guidepost, but chronic pain has lost this element. An early modern synonym of Schmerz is Pein (from OHG pîna and MHG pîne/pîn, from Latin poena, “penance, pu…