Forum speak, is when a thread is taken from one direction of discussion to another completely off course topic or many different topics in a short period of time.
The Canadian members on SXC are well known for hijacking many topics in the free photography communities forum.
by newbrand November 26, 2005
HiJack(Hy-Ja-K)-Verb
The action of forcefully taking an object, and using it for own purpose.

Or in other words-Kicking the crap outta some weakilng, taking his shit, and fucking inside-out.

Word Family:Hijack-Hijack-Hijacker
He hijacked my car!

And in other news, a band of wild-western bandits just hijacked a 20 century train, now how fucked up is TAHT!?

To hijack a browser.
by userdan December 17, 2005
A popular online pairing between Jack Overland Frost (Of Rise of the Guardians) and Hiccup Horrendous Haddock III (Of How to Train Your Dragon)
"Yeah I ship Hijack"
"But neither one of them are gay?"
"STFU"
by Aedan Frost March 23, 2013
A Hijacker could be defined as one who masturbates on a plane. This could also be considered as "sneaking into the mile high club."
Upon his return to the United States, the world traveler shares his experience of masturbating over the Atlantic Ocean. His only defense was "Who can't go 8 hours without choking it?" Phil rightfully names him the "Hijacker."
by MikeydaV May 18, 2006
1: Masturbating in a plane when in mid-flight(especially in the cock-pit)

2. Masturbating while stoned
Yesterday, I was hijacking in a hijacked plane
by PowerSerg June 16, 2011
noun.
An alternate name for a boxcutter or a similar knife-like tool as used by stock persons, shipping clerks, box packers, etc.

origin:
Related to the Sept. 11th destruction of the World Trade Center by airplanes. The boxcutter was the weapon of choice used by the terrorists that hijacked the airplanes.
The blade in my hijacker is getting dull.
by dfile July 26, 2004
Used as a form of greeting, specifically for a person named jack.
“Hijack! How did the game go last night?”
by ALittleBeeNamedHarold December 7, 2021