Multiple varieties of Arabic attest a definite noun + adjective syntagm in which only the adjective is marked morphologically with the article, e.g., Lebanese bēt iz-zġīr “the small house”. The feminine ending *-ah is everywhere realized -(v)t, e.g., Baghdadi sint il-māḍye “last year”. Most have assumed that it was originally appositional, and re-analysed as a construct, prompted perhaps by the loss of case (Hopkins 1984; Pat-El 2017). A few scholars (Reckendorf 1921; Retsö 2009) have argued that this syntagm was originally construct. In this article I draw on relevant Arabic data, including parallels with dialectal tanwīn, as well as comparative Semitic evidence, to argue that this syntagm is, diachronically and synchronically, one of apposition and not annexation. I propose that the feminine -at here represents a retention of proto-Arabic *-at, which was protected by the close relationship between a noun and following attribute. I conclude with a discussion of historical and comparative implications.