Hijack

Sometimes spelt highjack but more usually as hijack, an Americanism that dates from the 1920s, specifically the prohibition era, when shipments of liquor were stolen on the highways. Most sources maintain the origin is unknown but one or two maintain that the ‘hi’ or ‘high’ part derives from highway and the ‘jack’ part is or was slang for to lift or steal. This sounds plausible but is not proven. It was soon used figuratively, from the 1930s, for stealing or taking over anything e.g. ideas, plans, etc. Hijack in relation to stealing or taking control of aircraft dates from the 1960s.