jargon: 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 Debian possible default full paths are:

/usr/bin/jargon - from package: jargon

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