Zuckerberg (?z?k?b???) n (Biography) Mark (Elliot). born 1984, US internet entrepreneur; co-founder (2004) of social networking website FacebookCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014