Knock-Out is most commonly known as KO. It refers to an extremely violent punch. It is mostly used in the boxing field so as to indicate that one of the boxers completely faints after a punch of his rival. If the boxer who is victim of this violent punch does not recover and stands up within 10 seconds after he hit the floor, then, the referee considers the boxer lost the game.

However even if he recovers within the 10 seconds, the referees may stop the fight himself if he thinks the boxer is in danger after 3 K. Os in one round.
This is what is called the Technical Knock-Out (TKO).

A Knock-Out may be very dangerous: the boxer faints after he is usually hit in the head, whether on his forehead sides or jawbone. This is often compared to a slight coma. Scientists also compare it to the effect of a rocket or fighter liftoff: if the person was not correctly prepared, he or she may fall into a coma.

One of the greatest specialists of K. Os in the boxing field is obviously Mike Tyson, who, in 1995, did not wait more than 85 seconds to knock down his rival, McNeely.
His record is however far, far behind Chris Clement's K.O.: in 2006, during an MMA competition (Mixed-Martial Arts), he knocked his rival down (poor Laurato Tucas) in no more than 2 seconds!!

We would strongly advise you not to do that for real! You can however take it out on a virtual rival on our website!