wall-bound什么意思？

（关）在围墙里面的

大概是这么个意思。有上下文才能确保准确。

名词＋bound表示被局限在某个范围之内的，是个合成形容词。

再如：
I don't like being desk-bound all day.我讨厌整天呆在书桌旁。

They were brick-bound people who had no interest in growing things.这些人是在关在砖瓦房里长大的，对种植没兴趣。