This article investigates the vocabulary of astral sciences preserved in the Huihui Guan Zazi (回回館雜字), a Persian–Chinese glossary commissioned by the Ming imperial court in the early fifteenth century. Situating the text within the broader context of Mongol and post-Mongol Eurasian intellectual exchange, this article analyzes the glossary’s technical astronomy and astrology terms with attention to their precision, methods of translation, and the direction of knowledge transmission. The findings suggest a high level of conceptual translation and a bidirectional flow of knowledge, pointing to a multilingual environment sustained by close engagement with scientific texts under Mongol rule and retained in the early Ming. By contrast, supplementary materials within the glossary produced in the late sixteenth century reveal the erosion of this intellectual vitality, signaling the decline of Persianate influence within the Ming imperial bureaucracy.