phi·los·o·pher 
(fĭ-lŏsə-fər)
(fĭ-lŏsə-fər)n.
1. A student of or specialist in philosophy.
2. A person who lives and thinks according to a particular philosophy.
3. A person who is calm and rational under any circumstances.
[Middle English philosophre, from alteration of Old French philosophe, from Latin philosophus, from Greek philosophos, lover of wisdom, philosopher : philo-, philo- + sophiā, knowledge, learning.]