Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. Arnē, ēs, f., = Ἄρνη.
2. Arnē, ēs, f., = Ἄρνη, a woman who betrayed her country (the island Siphnos), and was changed into a jackdaw, Ov. M. 7, 465.