groovysh: 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/share/groovy2/bin/groovysh - from package: groovy2
/usr/share/groovy/bin/groovysh - from package: groovy

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

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