VTEC - Variable Valve timing and Lift Electronic Control and is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile. At low engine speeds, this rocker is not connected to any valves. At high engine speeds, a piston locks the extra rocker to the two rockers that control the two intake valves.

the thing that always kicks in, yo!

VTEC=Variable timing and lift electronic control.

variable valve timing and lift control. several other car companies use the same thing but with different acronims:
Honda: vtec
Nissan: VVL
Ford: VTC.
ect.

even though they are essentialy the same, each one dose have it's flaws for example:

vtec has very little torque.
VVL parts are rare and hard to come by.
VTC only works on the intake cam.

A "performance enhancing technology" employed by Honda in its "high-performance" "engines."

Variable valve Timing and lift Electronic Control.
engine's powerbands are limited to their cam lobe profile, by using multiple cam profiles, honda's VTEC system enables a much larger powerband. Not to be confused with VTECH electronics.

A term for Honda's valve timing system on most of their cars. Unfortunatly, it does not kick in until higher RPMs, thereby essetially doing nothing for acceleration. It's a poor excuse for losers in drag races.