buccaneering, carjack, piracy, skyjack.
backpacking, bushwhacking, carjacking, meatpacking, ransacking.
Your query has returned 76 words, which include anagrams of hijacking as well as other shorter words that can be made using the letters included in hijacking.
The words in this list can be used in games such as Scrabble, Words with Friends, Wordscapes and other similar games.