Anaximander, living about 610-546, wrote what is apparently the earliest book on philosophy, so he is another possible candidate for the "First Greek Philosopher" title.
The word "philosophy" comes from the Greek "philo" - "lover of" and "sophia" - wisdom. So a philosopher is a lover of wisdom. Many of them were highly educated and worked as teachers to the children of the wealthy; others worked more independently and were closer to modern research scientists. Others lectured publicly throughout Greece.