The standard doctrine for reacting to an ambush depends on how close it is triggered. The reaction to a NEAR ambush, from point-blank out to thirty meters, is to assault through. Since you are already in contact, seize the initiative. The reaction to a FAR ambush, thirty meters and further out, is to stop, pin the enemy and flank him.

Small unit tactics in these situations are brutally Darwinian. Now that it's possible to detect enemy concentrations with drones, the rules are changing as we watch the absolute mess that is playing out in Ukraine.

The root words of ambush refer to hiding in the bush or lure into the bush or woods. The technical or formal word in a military sense for an ambush is ambuscade, which comes from the French embuscade, which comes from the Italian imboscata "hiding in the bush." A faux Spanish verb ambuscado ,"attack from a concealed position" was popular in the 17th century.