light bulb moment

Word Origin for light bulb moment

C20: from the cartoon image of a light bulb lighting up above a character's head when he or she has an idea
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