From Longman Dictionary of Contemporary Englishfounder memberˌfounder ˈmember noun [countable] British English START something/MAKE something STARTsomeone who has helped to establish a new organization, club etc and is one of its first members SYN charter member American English
Examples from the Corpus
founder member• He is also a founder member and stage manager of the Calder Valley Junior theatre Society.• He was also a founder member of Bill Bruford's Earthworks, which has recorded four albums to date.• In 1884 he became a founder member of the Art Workers' Guild.• He is a founder member of the Prison Reform Trust.• He was a founder member of the Company of Master Mariners.• He was a founder member of the Edinburgh Press Club, established more than 50 years ago.• His work as a leading founder member was invaluable.From Longman Business Dictionaryfounder memberˌfounder ˈmember British English, charter member American English a person, organization, or country that helped to establish a new organization, club etc and is one of its first membersTogether with the Ukraine and the USSR, Belorussia became a founder member of the United Nations in 1945. → member 