Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Perseus.
Dēïănīra, ae, f., Δηϊάνειρα, daughter of Oeneus, sister of Meleager, wife of Hercules, and mother of Hyllus. She involuntarily caused the death of Hercules, by sending him the garment Nessus had given her, Ov. M. 9, 9 sq.; Hyg. Fab. 34 sq.; 162; Sen. Herc. Oet.; Cic. Tusc. 2, 8; id. N. D. 3, 28.