mysql - How to fix Warning: Use of undefined constant id - assumed 'id' (this will throw an Error in a future version of PHP) in PHP?

Warning: Use of undefined constant id - assumed 'id' (this will throw an Error in a future version of PHP) in /home/conteud2/public_html/include/meta.php on line 114

variate code using {var2[id]} no solution

Code in on comment below

You can check the issue on page https://www.conteudoanimal.vet.br/racaseespecies/anfibios/ver.php?id=5

Server runs PHP7 at moment

Thanks in advance for any help !