The Collaborative International Dictionary
Advancing edge
Advancing edge \Ad*van"cing edge\ (A["e]ronautics) The front edge (in direction of motion) of a supporting surface; -- contr. with following edge, which is the rear edge.
Advancing edge
Leading edge \Lead"ing edge\n.
(Aeronautics) the front edge of an airfoil; same as {Advancing edge}, above.
the front edge of anything that moves; also used metaphorically, as the leading edge in art. See also cutting edge.