名词眼镜堡，弦月窗，半圆壁
1. 月牙形低丘：lune 纬线弧 | lunette 月牙形低丘 | lunge 刺
2. 半圆壁：lunes 精神病发作 | lunette 半圆壁 | lung sac 肺囊
3. 凹凸两面透镜：Luneburglens卢纳堡透镜 | lunette凹凸两面透镜 | lung肺
4. 眼镜堡：lunette 弦月窗 | lunette 眼镜堡 | lunette 半圆壁
noun
1. oval or circular opening
to allow light into a dome or vault
Synonym: fenestella
2. temporary fortification like a detached bastion