What does "underdog" mean here?
Native speaker’s answer
Rebecca
"Underdog" in this video, is a common outdoor children's game. This game takes place on the swings. One child sits on the swing, and another child runs from behind, gives a big push to the swing, and runs under the swing as it goes over her head. Ex: The child gave the other an underdog on the swing set. Ex: When I was a kid, we used to give our friends underdogs when we played on the swings.