[knock out] vt (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