This radical is the same as the kanji. It means fault.

Just in case you don't remember the kanji's meaning mnemonic, here's the gist: That slide is your husband's only fault. He spends all day sliding down it like a madman, which is why his hair sticks straight up on top. Maybe that's another fault… It's also a way to remember this is 失 (fault), not 矢 (arrow).