war ‧ chalk ‧ ing /ˈwɔːˌtʃɔːkɪŋ $ ˈwɔːrˌtʃɒːk-/ BrE AmE noun [uncountable] technical
the activity of drawing symbols on the ↑ pavement to show the position of a ↑ wireless Internet network which ↑ hacker s can use to make a free connection to the Internet