terminology: 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/terminology - from package: terminology

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

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