LSJ
ἡ, the first day of the feast Apaturia, celebrated by public suppers in each phratria, personified in Philyll. 8.2; πρόπεμπτα τῆς Δ. IG 2.841b62; but τῆς ὁρτῆς τῇ δορπίῃ on the eve of the feast, Hdt. 2.48.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)