graph theory - 1. the study of graphs and networks.the study of graphs and networks. 2. the body of techniques used for drawing the graph of a function in the plane.the body of techniques used for drawing the graph of a function in the plane. ; дс тдрлими цюлютдажкию дроемжки аиакиохдйис лидр http://www.harcourt.com/dictionary/def/4/4/8/7/4487000.html;