plural knockouts
1
: an occurrence in which a boxing match ends when a fighter has been knocked down by a punch and is unable to start fighting again before 10 seconds have passed
He won the match by a knockout.
He scored a knockout in the fourth round.
2
informal
: a very attractive or appealing person or thing
She's a real knockout in that dress.
always used before a noun
1
: causing someone to become unconscious
a knockout punch/blow
2
informal
: extremely attractive or appealing
a knockout actress/movie
3
British, of a contest or competition
: designed so that winning teams or players continue to play and losing teams or players do not
The Wimbledon tennis tournament is a knockout competition.
Cite this Entry
“Knockout.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/knockout. Accessed 14 Apr. 2026.
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