To go beyond, or be superior to, on the flank; to pass around or turn the flank or flanks of.
go around the flank of (an opposing army)
to bracket an opposing disc or line of discs by placing a disc in such a way that the opposing disc or line lies between two opposing discs--one of which will be the disc just placed--with no spaces intervening; outflanked discs are captured and flipped to the color of the discs that outflanked them