offering a challenge; testing one's ability, endurance, etc: a challenging course; a challenging game.
stimulating, interesting, and thought-provoking: a challenging suggestion.
provocative; intriguing: a challenging smile.
Origin of challenging
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
demanding or stimulatinga challenging new job
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