Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Nyctēgrĕsĭa, ae, f., = Νυκτηγρεσία (Νυκτεγερσια), Night-watching, the title of a tragedy of Attius (v. Trag. Rel. Fragm. p. 168 Rib. sq.).