synergyd: 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/synergyd - from package: synergy

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

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