How do I stop one product from appearing in Google search?

1. Go to Products → Products and open the product.
2. Scroll to the Search engine listing card and click + Edit SEO if the fields are hidden.
3. Set Search indexing to noindex.
4. Click Save.

This tells search engines not to list the product page. Link following works the same way: nofollow tells search engines not to follow links from that page.

The product stays on your store for shoppers. If Google has already listed the page, it can take a while to drop out after Google visits again.