expression, ichidan verb
press one's head into the opponent's chest to stop them
Sumo technique where a wrestler drives their head into the opponent's chest to halt their advance or control their posture.
力士は相手の胸に頭を付けて攻めを止めた。
The sumo wrestler pressed his head into his opponent's chest and stopped the attack.
Compound of 頭 (head) + を + 付ける (attach, press against). The exact origin as a sumo term is uncertain.