bulwark

1. N-COUNT A bulwark against something protects you against it. A bulwark of something protects it. 防护; 堡垒[oft N 'against/of' n]

The abbeys were founded in the 12th century by King David as a bulwark against the English. 这些修道院是大卫王于12世纪修建的抵抗英国人的堡垒。