csh: 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 CentOS possible default full paths are:

/bin/csh - from package: tcsh

You may install the required package with command yum install {package}

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