#1 knock out v. eliminate; "knock out a target". wn #2 knock out v. knock unconscious or senseless; "the boxing champion knocked out his opponent in a few seconds". wn #3 knock out v. destroy or break forcefully; "The windows were knocked out". wn #4 knock out v. overwhelm with admiration; "All the guys were knocked out by her charm". wn #5 knock out v. empty (as of tobacco) by knocking out; "knocked out a pipe". wn