From Longman Dictionary of Contemporary Englishfreethinkerfree‧think‧er /ˌfriːˈθɪŋkə $ -ər/ noun [countable] INDEPENDENT PERSONsomeone who has their own opinions, ideas, and beliefs, rather than accepting other people’s – used to show approval —freethinking adjective
Examples from the Corpus
freethinker• In matters of religion, Montgomery was a freethinker. 