صحراء [Imperfectly declined though not an epithet, or it is an epithet in which the quality of the substantive predominates, and is imperfectly declined because it is of the feminine gender, and because the letter characteristic of the feminine gender is inseparable from it]…
-Lane’s Lexicon, Explanatory Note to the word entry Sahrā’, under the triliteral root S H R, alongside the words Suhār, Horse Sweat, and Sahīr, Uttering of an Ass
…“A Desert…”