Our detectives are back with the following intel on this WordPress site
The site is using the WP Glossary theme by Anders Norén .
We could identify 2 plugins (there might be more) -
WP Super Cache
This information was last updated 22 February, 2019
Theme for WP Glossary.
Protection from login, registration and reset-password brute-force attacks. No captcha.
A very fast caching engine for WordPress that produces static html files.