warchalking (?w??t???k??) n (Computer Science) the practice of marking chalk symbols on walls and pavements at places where local wireless internet connections may be obtained for free via a computer, usually without permission[C21: from w(ireless) a(cess) r(evolution) + gerund of chalk] ?warchalker nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014