C2 noun /ˈfriːˌθɪŋkər/
freethinker
自由思想家
Meaning
A person who forms opinions based on reason and independent thought rather than tradition or authority.
Example
Voltaire was considered a great freethinker of his time.
ヴォルテールは彼の時代の偉大な自由思想家と見なされていました。