An ambush is a surprise attack carried out by combatants waiting in a concealed (and typically well-defiladed) position against an approaching enemy individual or group. The concealed position itself or the concealed person(s) may also be called an "ambush", and the chosen area to carry out the ambush is known as the kill zone or the trap.
The term "ambush" is also used in animal behavior studies to describe the predation strategy of some carnivores using stealth and deception (i.e. ambush predators), in sociology to describe aggressive journalistic practices (i.e. ambush journalism), and in economics to describe some marketing strategies (i.e. ambush marketing), all of which involve an element of surprise upon the recipients.