tag2thesaurus: 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/tag2thesaurus - from package: libbiblio-thesaurus-perl

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

Error in other languages:
tag2thesaurus: bevel nie gevind nie
tag2thesaurus: comandă negăsită
tag2thesaurus: comando não encontrado
tag2thesaurus: commande introuvable
tag2thesaurus: command not found
tag2thesaurus: käsku ei ole
tag2thesaurus: không tìm thấy lệnh
tag2thesaurus: komanda nerasta
tag2thesaurus: Kommando nicht gefunden.
tag2thesaurus: kommandot finns inte
tag2thesaurus: komut yok
tag2thesaurus: nie znaleziono polecenia
tag2thesaurus: níor aimsíodh an t-ordú
tag2thesaurus: no se encontró la orden
tag2thesaurus: no s'ha trobat l'ordre
tag2thesaurus: opdracht niet gevonden
tag2thesaurus: parancs nem található
tag2thesaurus: perintah tidak ditemukan
tag2thesaurus: príkaz nenájdený
tag2thesaurus: příkaz nenalezen
tag2thesaurus: команда не найдена
tag2thesaurus: командата не е открита
tag2thesaurus: 命令找不到
tag2thesaurus: コマンドが見つかりません