1) Content management system 2) Web framework 
Drupal əl is a free and open-source content management framework written in PHP and distributed under the GNU General Public License. It is used as a back-end framework for at least 2.1% of all Web sites worldwide ranging from personal blogs to corporate, political, and government sites including WhiteHouse.gov and data.gov.uk. It is also used fo...
• (a.) Drupaceous.
Drup'al adjective (Botany) Drupaceous. 
— A popular content management system known for a vibrant open-source community that creates diverse and robust extensions. Drupal is very powerful, but it is somewhat difficult to use for simple tasks when compared to WordPress. Drupal provides options to create a static website, a multi-user blog, an Internet forum or a community website f...