knockout
knock‧out1 /ˈnɒk-aʊt $ ˈnɑːk-/ 
noun [countable]
1. when a boxer hits his opponent so hard that he falls down and cannot get up again:
The fight ended in a knockout.
2. informal someone or something that is very attractive or successful:
Her dress was a knockout.
3. a type of competition in which only the winning players or teams at each stage continue to play until there is only one winner
knockout2 adjective informal
1. knockout punch/blow
a. a hard hit that knocks someone down so that they cannot get up again
b. an action or event that causes defeat or failure:
High interest rates have been a knockout blow to the business.
2. relating to a type of competition in which only the winning players or teams at each stage continue to play:
Scotland’s failure to get through the knockout stage of the competition
3. knockout pills/drops etc pills etc that make someone unconscious
| I |
noun [countable]1. when a boxer hits his opponent so hard that he falls down and cannot get up again:
2. informal someone or something that is very attractive or successful:
3. a type of competition in which only the winning players or teams at each stage continue to play until there is only one winner
| II |
adjective informal1. knockout punch/blow
a. a hard hit that knocks someone down so that they cannot get up again
b. an action or event that causes defeat or failure:
2. relating to a type of competition in which only the winning players or teams at each stage continue to play:
3. knockout pills/drops etc pills etc that make someone unconscious