Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pydna, ae, f., = Πύδνα, a city in Macedonia, on the Thermaic Gulf (the modern Kitro), celebrated for the battle in which Perseus was defeated by Æmilius Paulus, Liv. 44, 6, 3; 44, 42, 2 sqq.; Nep. Them. 8, 5.
Pydnaei, ōrum, m., the inhabitants of Pydna, Liv. 44, 45.