A technical knock-out (TKO) is a special term used in boxing, considered by the judges, when one boxer seems too wounded to continue.
In the Punch-Out!! games, when a boxer forfeits the match after being knocked down a certain numbers of times. In the NES, SNES, and Wii editions of Punch-Out!!, a TKO occurs after a boxer is knocked down three times within a single round. There are some opponents who can only be beaten by TKO.
In Punch-Out!! for the Wii, Little Mac can save himself from a knockout loss with the KO Recovery trick. If successfully executed, Mac will suddenly put his right foot down just as he is about to fall on his knees and yell angrily, then the fight will continue with Mac regaining half his health.