noun
breastwork; parapet (military)
Military fortification term: a low defensive wall or earthwork, often temporary, used to protect soldiers.
See also: 胸墻
兵士たちは胸壁の陰に身を隠した。
The soldiers took cover behind the breastwork.
noun
Rare, literary use for a fortified place or stronghold; not a common standalone word for fortress in modern Japanese.
その古城は難攻不落の胸壁として知られていた。
The old castle was known as an impregnable fortress.
noun
Architectural term for a low protective wall at the edge of a roof, balcony, bridge, or terrace.
See also: パラペット
屋上の胸壁から街を見下ろした。
I looked down at the city from the parapet on the rooftop.
noun
chest wall
Medical/anatomical term for the thoracic wall; used in clinical contexts.
胸壁の手術は専門医が行った。
The chest wall surgery was performed by a specialist.