Mona Lisa (?m??n? ?li?z?) n (Art Terms) a portrait of a young woman painted by Leonardo da Vinci, admired for her enigmatic smile. Also called: La Gioconda Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014