Dictionary.com
definitions

adaptogen

noun
  1. any of various natural substances used in herbal medicine to normalize and regulate the systems of the body

Word Origin for adaptogen

C20: from adapt + -gen
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012