conventicle
/kənˈventɪkl/noun
- historical a secret or unlawful religious meeting, typically of people with nonconformist views〈史〉（尤指非国教徒举行的）秘密（或非法）宗教集会。
词源
late Middle English （in the general sense 'assembly, meeting', particularly a clandestine or illegal one）： from Latin conventiculum '(place of) assembly', diminutive of conventus 'assembly, company', from the verb convenire （see CONVENE）.