εἰκοσασταδίῳ
εἰκοσαστάδιος, of twenty stadia
Morpho works with a static database. If you like, you can compare the output of Morpheus.
Parsed as:
masculine dative singular
feminine dative singular
neuter dative singular of
εἰκοσαστάδιος
No checked forms of εἰκοσαστάδιος in the morphology database.