In the enclosure sense, as indicated by SH above, it's the same as our modern word pound in the way we use it for dog-pound, for example...ie a closed area where stray dogs are kept.
...just kidding, Postdog - I've often noticed that people come up with different search results not just depending on their search strings and search engines but also on what country they're in, and I'm in Sweden and probably you're not.