OWASP
/ˈoʊ.wɒsp/ · Abbreviation · Security & Infosec · Origin: 2001
Definitions
Open Web Application Security Project — a nonprofit foundation producing tools, documentation, and the famous Top 10 list of web application security risks. If you haven't read the OWASP Top 10, you haven't done web security.
In plain English: A free, community-driven organization that publishes the most widely referenced list of web security risks and how to prevent them.