gvim: 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:

/usr/bin/gvim - from package: vim-X11

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

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