a puzzle or problem whose solution requires great ingenuity.
Origin of brainteaser
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Related Words for brain-teaserriddle, mystery, enigma, puzzlement, poser, mystification, problem, why, brain-teaser
informal a difficult problem
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