charter member
noun🔊/ˌtʃɑːtə ˈmembə(r)/
🔊/ˌtʃɑːrtər ˈmembər/
(also founding member)
(both North American English) (British English founder member)
one of the first members of a society, an organization, etc., especially one who helped start it （社团、组织等的）创始人，发起人，创建人