The gap in fiqh al-muʿamalah terminology in classical Islamic jurisprudence and its use in contemporary Islamic economic practices raises interpretive issues with implications for the normative construction of Islamic economic law. This study analyzes the semantic shifts in the terminology of fiqh al-muʿamalah, including its adaptation in contemporary Islamic finance practices and its implications for the development of Islamic economic law. By adopting a qualitative approach that combines linguistic-semantic and normative-comparative analysis, the legal materials studied include classical Islamic texts, Fatwas of the National Sharia Board-Indonesian Ulema Council, standards of the Accounting and Auditing Organization for Islamic Financial Institutions, and the Islamic Financial Services Board. The research findings indicate that terms such as bayʿ, riba, mudarabah, musharakah, and gharar are subject to expansion, narrowing, contextual adaptation, and recontextualization along with the development of the modern Islamic financial system. These shifts are semantic and reflect epistemological and normative transformations, particularly regarding the harmonization of classical Islamic principles, national regulations, and modern financial industry needs. These findings confirm that the terminology of fiqh al-muʿamalah is not static but continues to transform along with social, economic, and regulatory dynamics, while maintaining coherence with the principles of Islamic law. This study enriches the discourse on Islamic economic law by offering a conceptual framework regarding the transformation of fiqh al-muʿamalah terminology as a normative adaptation mechanism enabling harmonization between maqaṣid al-shariʿah,the needs of regulations, and Islamic economic globalization demands.