The Anti-Defamation League (ADL) has launched an online Glossary of Extremism, an interactive and searchable database that provides definitions of common and obscure terms related to extremism and extremist groups. Describing it as “a first-of-its-kind interactive and searchable database providing comprehensive definitions of commonly known and more obscure terms employed by a variety of groups and movements across the extremism landscape,” the ADL database has definitions of around 900 terms and concepts used by a variety of extremist groups and movement, including white supremacists, antisemites, Islamist extremists and single-issue extremists such as ecoterrorists and incels. The database was created by...