ambush/ ˈæm bʊʃ /
noun also am·bush·ment.
an act or instance of lying concealed so as to attack by surprise:
The highwaymen waited in ambush near the road.
an act or instance of attacking unexpectedly from a concealed position.
the concealed position itself:
They fired from ambush.
those who attack suddenly and unexpectedly from a concealed position.
verb (used with object)
to attack from ambush.