Pheidippides Syllabification: (Phei·dip·pi·des)Pronunciation: /fīˈdipiˌdēz/Definition of Pheidippides (5th century bc), Athenian messenger. He was sent to Sparta to ask for help after the Persian landing at Marathon in 490 and is said to have covered the 150 miles (250 km) in two days on foot. Pheidippides in other Oxford dictionaries Definition of Pheidippides in the British & World English dictionary