Honda's name for their variable valve timing system that happens to include electronic lift control. (See also : MIVEC, VVTL-i, VariCam Plus, VANOS, and VVL. )
For combustion engines, it allows the increase of air and fuel consumption when VTEC is engaged.
Due to its "lift control", VTEC doesn't engage until higher RPMs to save fuel. Once engaged however, fuel economy drops significantly as performance increases by 20 - 30 horsepower with an increase of torque efficiency.
To market their "economy" cars, Honda used VTEC to have higher horse-power claims. Most of their horsepower claims are at high RPM marks (7,500 or higher), whereas other motor companies make their claims at lower RPM marks (5,500 or below).
This confused most buyers as they thought that engaging their VTEC would allow for them to enjoy peak fuel economy AND peak performance at the same time (hence grew the term to mock VTEC-users; "vtak just kicked in yo!")
To add to the illusion of performance (but keep the status of "economy car"), most VTEC-motors were dropped into chassis with a front-wheel drive drive train (with the S2000 and NSX exempt).
Due to their front-wheeled drive pull, some VTEC users became euphoric in what seemed to be a "fast" car(though it was mostly because of the "pull" force from the car being a FWD vehicle).
Ultimately, the concept of variable valve timing and lift control is now used by other car companies.
Person A : "I got a VTEC motor." *Grin*
Person B : "I bet that guy is a ricer."
"My RSX goes 0-60 in 7.8 seconds. It's got a VTEC."
Person B : "Dude, why do you have that gay looking spoiler on your Civic?" :/
Person A : "Are you stupid or something! Dude, it's got a VTEC. There has to be something to hold down its rear-end or I could spin the fuck out!"