am´boosh (×רב, 'aÌ„rabh, “to set an ambushâ€; מ×רב, maÌ„'ăraÌ„bh, “an ambushâ€): A military stratagem in which a body of men are placed in concealment to surprise an enemy unawares, or to attack a point when temporarily undefended. This stratagem was employed successfully by Joshua at Ai (Josh 8). Jeremiah calls upon the Medes to “set up a standard against the walls of Babylon, make the watch strong, set the watchmen, prepare the ambushes†().