Someone who studies or writes about the meaning of life
EX: Confucius was a Chinese philosopher
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Merriam-Webster Online Dictionary
philosopher (noun)1.
a) a person who seeks wisdom or enlightenment - scholar thinker
b) a student of - philosophy
2.
a) a person whose perspective makes meeting trouble with equanimity easier - philosophical
b) an expounder of a theory in a particular area of experience
c) one who - philosophizes