The word "highjackings" has several synonyms that you can use to describe such an event. Some of the synonyms for highjacking or highjackings include piracy, hijacking, skyjacking, carjacking, and even theft. Piracy refers to taking over a vessel, while hijacking usually relates to an airplane. Skyjacking is also associated with hijacking aircraft, while carjacking refers to taking control of an automobile. Other synonyms that can describe the act of stealing or taking over a vehicle or vessel include commandeering, robbing, seizing, and kidnapping. It is essential to use the right word when describing a particular crime. Using precise synonyms will help your audience understand the matter at hand better.