Knockout

From knock out.

Full definition of knockout

(plural knockouts)

The act of making someone unconscious, or at least unable to come back on their feet within a certain period of time; a TKO.The boxer scored a knockout on his opponent.
The deactivation of anything.

1989, Network World (6 February 1989, page 82)Pull the plug on a node to see how the network handles a node knockout.

(informal) Something wildly popular, entertaining, or funny.If you've ever had a sack race, you know it's a real knockout for kids and adults alike.
(informal) A very attractive person, especially a beautiful woman.

1995, Rhonda K. Reinholtz et al., "Sexual Discourse and Sexual Intercourse," in P. J. Kalbfleisch and M. J. Cody, eds., Gender, Power, and Communications in Human Relationships, p. 150,Phrases such as "she bowled me over," "she's striking," and "she's a knockout" suggest that the woman affects the man in ways he cannot mediate or control.

A partially punched opening meant for optional later removal.They left a knockout in the panel for running extra wires someday.
(genetics) The deactivation of a particular gene.
(genetics) A creature engineered with a particular gene deactivated.
(printing) An event where a foreground color causes a background color not to print.
(sports) A tournament, in which a team or player must beat the opponent in order to progress to the next round.the knockout stages of the competition

2011, November 3, Chris Bevan, Rubin Kazan 1 - 0 Tottenham, In truth, Tottenham never really looked like taking all three points and this defeat means they face a battle to reach the knockout stages -with their next home game against PAOK Salonika on 30 November likely to prove decisive.

Rendering someone unconscious.He delivered a knockout blow.
Amazing; gorgeous; beautiful.You should have seen her knockout eyes.
(genetics) Designating an organism in which a particular gene has been removed or deactivated.

1999, Matt Ridley, Genome, Harper Perennial 2004, p. 255:The result is a so-called knockout mouse, reared with a single gene silenced, the better to reveal that gene's true purpose.

2012, Ben Smith, Leeds United 2-1 Everton http://www.bbc.co.uk/sport/0/football/19632366Rodolph Austin delivered the knockout blow from close range 20 minutes from time, after Aidan White had given Leeds a dream start after four minutes.