Main Entry: knock out

Function: transitive verb

Date: 1856

1 : to produce roughly or hastily
2 a (1) : to defeat (a boxing opponent) by a knockout (2) : to make unconscious <the drug knocked him out> b : to make inoperative or useless <electricity was knocked out by the storm> c : to get rid of : eliminate <knocked out illegal gambling>
3 : to tire out : exhaust <knocked themselves out with work>
4 : to cause (an opposing pitcher) to be removed from a baseball game by a batting rally