The Collaborative International Dictionary of English v.0.48:

Philhellenist \Phil*hel"len*ist\, n. [Philo- + Gr. "E`llhn a
   Greek: cf. F. philhell[`e]ne.]
   A friend of Greece; one who supports the cause of the Greeks;
   particularly, one who supported them in their struggle for
   independence against the Turks; a philhellene.
   [1913 Webster]

WordNet (r) 3.0 (2006):

philhellenist
    n 1: an admirer of Greece and everything Greek [syn:
         philhellene, philhellenist, Graecophile]