The earliest reference to "hijack" that OED lists is from 1923.
1923 Lit. Digest 4 Aug. 51/3 ‘I would have had $50,000,’ said Jimmy, ‘if I hadn't been hijacked.’
But the etymology is listed as unknown.
Interestingly, I found several newspaper references to a poker game robbery in 1920 that seem to antedate the OED quote, although they all used a hyphen.
- The Democrat-American 09 Jan 1920, Fri (paywall)
Looking further, I found a 1916 newspaper reference to "hijacks," also referring to a poker game.
Given that these references are poker-related, my immediate hunch was that the term may have originated as a gambling term. This doesn't seem far-fetched to me; Winning a poker hand with a high-card jack would be a figurative robbery of sorts in some poker variants.
Etymonline offers an alternative explanation:
American English, perhaps from high(way) + jacker "one who holds up" (agent noun from jack (v.)).
This explanation makes sense but appears to me to be a little bit misleading. It makes it sound as though "jacker" meant "someone who holds people up," i.e. robs them, but it actually seems to refer to "jack" as in "to hoist something up on a jack."
Having researched this into the two separate directions, I thought it was time to post a question.
- Is there any corroborating or invalidating evidence to the theory that "hijack" could have started as a gambling term?
- Is there evidence beyond speculation that it derives from hoisting a stolen good up with a jack?