An ambush, also known as a sneak attack or bushwhacking was a tactical maneuver in which combatants remained concealed and use the element of surprise to their advantage against their opponents.
In 2267, the Gorn executed the perfect ambush on the crew of the USS Enterprise, by first attacking and destroying the outpost on Cestus III, before luring the ship there under the guise of an invitation from the outpost Commodore Travers. (TOS: "Arena")
In 2268, during a Melkotian re-creation of the Battle at the OK Corral, "Ike Clanton" (James T. Kirk) was advised by Johnny Behan to bushwhack the Earps when they arrived at the O.K. Corral. Kirk rejected it, saying he couldn't murder them. (TOS: "Spectre of the Gun")
Later that year, Kang accused Captain James T. Kirk of luring his ship into an ambush near Beta XII-A by a false Klingon distress call; Kirk countered that "Federation ships don't specialize in sneak attacks." (TOS: "Day of the Dove")