highjack vs hijack

highjack and hijack both are nouns.

Word	Noun	Adjective	Verb	Adverb
highjack	Yes	No	Yes	No
hijack	Yes	No	Yes	No

As nouns, highjack and hijack are synonyms defined as:

highjack and hijack: seizure of a vehicle in transit either to rob it or divert it to an alternate destination

As verbs, highjack and hijack are synonyms defined as:

Other synonyms of highjack include commandeer, pirate.

highjack (noun)	hijack (noun)
seizure of a vehicle in transit either to rob it or divert it to an alternate destination	seizure of a vehicle in transit either to rob it or divert it to an alternate destination

highjack (verb)	hijack (verb)
take arbitrarily or by force	take arbitrarily or by force
	seize control of