يَوْمُ عَرَفَهَ

The ninth day of [the month] ذُو الحِجَّة [when the pilgrims halt at عَرَفَات]: (S, Mgh, O, Msb, K:) the latter word being without tenween, (S, O,) imperfectly decl., because it is of the feminine gender and a proper name, (Msb,) and not admitting the article ال. (S, O, Msb.)

See also the next paragraph.