Fetching details from the dictionary...

trunk; torso; body; abdomen; waist
plastron (in kendo); touching the plastron (kimari-te in kendo)
frame (of a drum, etc.); sound box (of a shamisen, etc.); hull (of a ship)
剣道では胴を打つ技術が試合の勝敗を左右する。
In kendo, the technique of striking the torso can determine the outcome of a match.
この犬種は胴が長く足が短いのが特徴である。
This breed of dog is characterized by a long body and short legs.
太鼓の胴は一本の木をくり抜いて作られている。
The body of the drum is made by hollowing out a single piece of wood.