unmunch: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/unmunch - from package: hunspell-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/unmunch - from package: hunspell-tools
/usr/bin/unmunch - from package: myspell-tools
/usr/lib/debug/usr/bin/unmunch - from package: libhunspell-1.3-0-dbg

You may install the required package with command apt-get install {package}
Error in other languages:
unmunch: bevel nie gevind nie
unmunch: comandă negăsită
unmunch: comando não encontrado
unmunch: commande introuvable
unmunch: command not found
unmunch: käsku ei ole
unmunch: không tìm thấy lệnh
unmunch: komanda nerasta
unmunch: Kommando nicht gefunden.
unmunch: kommandot finns inte
unmunch: komut yok
unmunch: nie znaleziono polecenia
unmunch: níor aimsíodh an t-ordú
unmunch: no se encontró la orden
unmunch: no s'ha trobat l'ordre
unmunch: opdracht niet gevonden
unmunch: parancs nem található
unmunch: perintah tidak ditemukan
unmunch: príkaz nenájdený
unmunch: příkaz nenalezen
unmunch: команда не найдена
unmunch: командата не е открита
unmunch: 命令找不到
unmunch: コマンドが見つかりません