a person whose opinions, especially about religion or politics, are extreme, and who may do things that are violent, illegal, etc. for what they believeleft-wing/right-wing/political/religious extremistsHe was assassinated by extremists.Oxford Collocations Dictionaryadjectiveleft-wing,right-wing,radical,…extremist + nounelement,group,movement,…Seefull entryWordfinderattackalert,assassinate,attack,campaign,execute,extremist,hijack,hostage,kidnap,terrorism
See extremist in the Oxford Learner's Dictionary of Academic EnglishSee extremist in the Oxford Advanced American Dictionary