Discussion and research in different rhetorical and semantic aspects of the Quran, and especially the syntactic and rhetorical aspects, have astonished the Quranic researchers of every age. Among these rhetorical issues is the discussion of the Tanwin and its hidden intentions and purposes. This unique phenomenon of the Arabic language, which is widely used in the Holy Quran, has other secondary meanings that are sporadically mentioned in the syntactic books, in addition to its original meaning (indicating indefinite noun). By carefully reflecting on the Quranic verses, it appears that the Tanwin has other implications such as, amongst other things, magnification, reduction, proliferation, diversification, humiliation, generalization. A field survey of the Farsi translations of the Quran shows that most translators have not paid much attention to the Tanwin and its other semantic implications, and have largely meant it to indicate indefinite nouns. In this study, it has been attempted to criticize and analyze the semantic aspects of the Tanwin and its different implications in some of the Quranic verses translation by Abdurrahman Pirani et al. The results show that paying attention to the semantic and implicating dimensions of the Tanwin can be an effective step towards enhancing the semantic levels of Quranic expressions and discovering the rhetorical-semantic layers of this divine book. But this translation, along with many of its more prominent features, does not pay much attention to the secondary meanings of the Tanwin, and this has led to some divergence from some of the sublime meanings and concepts in the Quranic vocabulary.