Body
The radical is the same as the kanji, so it means body.
Just in case you need a refresher, here's the mnemonic again: When your self goes down a slide and hits a barb, it's a painful reminder that you have a body. Sometimes people think their self is just some kind of floating, disembodied consciousness, but getting a barb stuck in oneself while going down a slide will quickly remind one of one's bodily existence.