The Collaborative International Dictionary
Philo-
Philo- \Philo-\ A combining form from Gr. fi`los loving, fond of, attached to; as, philosophy, philotechnic.
Douglas Harper's Etymology Dictionary
philo-
before vowels phil-, word-forming element meaning "loving, fond of, tending to," from Greek philo-, comb. form of philos "dear" (adj.), "friend" (n.), from philein "to love," of unknown origin. Productive of a great many compounds in ancient Greek.
Wiktionary
philo-
pre. (alternative form of phil- English)