gforthmi: command not found

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/gforthmi - from package: gforth

You may install the required package with command apt-get install {package}

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