knock out cold

knock someone out cold は殴って気絶させるくらいの意味です。0;08 you can see the two talking. when he tries to force Keith onto the hood of his car, when she resists,,,, Keith is knocked out cold.

Video shows cop knocking DWI suspect out
https://www.youtube.com/watch?v=zYb2yI1sBTU  1:02 the rush hits you within seconds. after just 30 minutes, heroin can knock you out cold.
https://www.youtube.com/watch?v=7ovyzkRmdVU  4:55 soon Jesicaa is (knocked) out cold.

参考リンク
https://www.youtube.com/watch?v=p2EDkv_dyeI  2:20 You've got the cutest ass I've ever seen, knock me down for a six anytime

練習問題解答
a-5159 knocked out cold
b-2598 knocking him out cold