We present a statistical analysis of the realization of definiteness in Tunisian Arabic (TA) texts written in Arabizi, a hybrid system reflecting some features of TA phonetics (assimilation), but also showing orthographic features, as the use of arithmographs. In §1, we give an overview of definiteness in TA from a semantic and syntactic point of view. In §2 we outline a typology of definite articles and show that TA normally marks definiteness with articles or similar devices, but also presents (...) zero-markings or weak definites. In §3 we discuss TA and how definiteness is instantiated in TA. In §4, we present data from the Tunisian Arabizi Corpus (TAC), a multidisciplinary work with a hybrid approach based on dialectological questions, corpus linguistics standards, and deep learning techniques. In §5 we define the behavior of TA with respect to what we observed in §1, §2 and §3, describing our TAC-based analysis. (shrink)