What is the meaning of Tag_out?

To affix a label to (potentially dangerous machinery) to indicate why it has been shut down. To avoid accidents, only the person who affixed the label is authorized to remove it and restart the machinery.

To touch a contestant or player in order to do something, such as to remove a runner from play in baseball or to replace a wrestler with a teammate in tag-team wrestling.

To replace another person or take another person's place, such as in a shift change at a workplace.

To be replaced by another person, such as in a shift change.

Source: wiktionary.org