How to kill zombie process

I launched my program in the foreground (a daemon program), and then I killed it with kill -9, but I get a zombie remaining and I m not able to kill it with kill -9. How to kill a zombie process? If the zombie is a dead process (already killed), how I remove it from the output of ps aux? root@OpenWrt:~# anyprogramd & root@OpenWrt:~# ps aux | grep anyprogram 1163 root 2552 S anyprogramd 1167 root 2

[prozorec]

zombieという名前から死んでいるのは自明だが、kill -HUP $(ps -A -ostat,ppid | grep -e '[zZ]'| awk '{ print $2 }')でリストから削除できそう？