To change the name 'Product' to 'Properties' in the Odoo 15 Website, you will need to edit the website templates and translatable strings in the website module. Here is a general outline of the steps you can follow to make this change:

Enable the Developer Mode in your Odoo instance by going to the Settings menu and selecting the "Activate the developer mode" option.

Navigate to the website module and find the templates and translatable strings that contain the text 'Product'. These may be located in the 'views' and 'static/src/js' directories.

Edit the templates and translatable strings to replace the text 'Product' with 'Properties'.

Save your changes and reload the website to see the updated text.

Note that this process may be different depending on the specific customization and modules you have installed in your Odoo instance. It is always a good idea to make a backup of your database before making any significant changes to your system.

I hope this helps! Let me know if you have any further questions