knock someone's/something's socks off, knock your socks off

자료: http://idioms.thefreedictionary.com/sock

knock someone's/something's socks off

to completely defeat a competitor. 

• Japan and Korea knocked the socks off the United States in tests of science and math.
  

See also: knock

knock your socks off

to completely surprise or please you very much. 

• The magazine is beautiful and combines color and unusual design in a way that knocks your socks off.

Usage notes: also used with other verbs to say that something is done in an extreme way or to a great degree:

•  I worked my socks off to get my degree.
  

See also: knock

Cambridge Dictionary of American Idioms © Cambridge University Press 2003