v surround with a wall in order to fortify
a. 有城墙的
1. The garden is walled to keep out animals.
花园被围起来以防止动物进入。
2. They live in a walled city that dates back to the 15th century.
他们住在一座可以追溯到15世纪的城墙围绕的城市里。
3. The children played safely inside the walled playground.
孩子们在围起来的操场里安全地玩耍。