rampart
/ˈræmpɑ:t; `ræmpɑrt/ n
1 (esp pl 尤作复数) defensive wall round a fort, etc consisting of a wide bank of earth with a path for walking along the top （城堡等周围宽阔的）防御土墙.
2 (esp sing 尤作单数) defence; protection 防御; 保护
a rampart against infection 对传染病的预防.