Since define() is the core part, this indicates that one or more of the following is true:

• define Functions are listed in disable_functions of php.ini
• Loads some kind of hardened module that disables it and requires configuration
• Your PHP installation is completely corrupt and needs to be repaired

If you are not the administrator of the server, you can ask them if one of these applies to the server. If you are an administrator, you can take a look at php.ini. If everything works fine, then you need to reinstall PHP.