Overclock - to raise the speed of the CPU, GPU, memory, or any buses with the quantifier that tells its speed: "hertz".

To overclock is to force some hardware mentioned above to run at faster, often non-intented speeds.
Generally this is doable, however few factors come in such as when one overclocks a piece of hardware to its max the power circuitry usually does not deliver enough voltage to the hardware, thus the voltage needs to be manually raised.

When raising the voltage, heat will be generated more substantially, which is the hardware's number one enemy.

Thus is why companies like Thermaltake and Globalwin have mustered their efforts to produce efficient and powerful cooling systems to counteract the heat.
Using the motherboard's BIOS. I set the FSB to 210mhz, thus overclocking a 10mhz difference on my FSB.

I used RivaTuner to overclock my video card's memory's clock speed from 250mhz to 305mhz.
by Andrew the kool January 1, 2004
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To raise the clock speed of a graphics processing unit, central processing unit, or memory module by raising the front side bus (FSB) or the multiplier.

The end clock speed is determined by using the following equation

Multiplier * FSB = mhz

Sometimes additional voltage is required to achieve higher speeds.

Overclocking almost always requires more cooling than "stock" parts provide. And generally shortens the life of a componant.
I overclocked my Athlon by unlocking the multiplier and upping the FSB. I had to add .5v to make it stable though.
by Shayne September 29, 2003
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To raise the stock speed of a GPU or CPU. People who can overclock are awesome.
In order to overclock, I had to raise the Vcore.
by Charles Ray March 21, 2003
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The process of installing high hopes, dumb luck, and several paychecks into a rectangular
box which transmits a signal to a screen that displays your fate. The outcome is usually depressing.
After i spent $500 on overclocking equipment the screen told me i was going to die tomorrow
by Eggtacular July 7, 2006
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Increase in clock speed through transistors, usually done to video cards and processors.
Trevor would get hot along with his video card whenever he overclocked.
by Q_unreal October 11, 2005
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I overclocked that CPU to 3.2GHz, it's got wicked overclockability.
by grubby91 January 21, 2006
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