This study aims at highlighting the rhetorical inimitability of synonymous words in different contexts of the Holy Quran, by studying 42 spatial and temporal Quranic terms and their contexts. It studies some synonymous terms in the Holy Quran that have similar meanings and different morphology. Some of these were used interchangeably in Tafseer books to interpret Quranic verses. Dictionaries are often restricted to terms that seemed not to be classified and studied as synonymous terms. Some of these terms might have been studied before but the study aims at adding more to it. The study applies an inductive approach on each of the selected terms in their Quranic context, then compares and contrasts them which leads to dividing them into fifteen groups of two or more synonymous terms. Then their differences are indicated by tracing their origins, studying Tafseer books, Quranic Science books and other related books. Terms were examined from a rhetorical aspect in order to broaden the scope of differences between terms. The study covers more than lexical values, as it studies the connotations of these terms in their Quranic context. This adds variable rhetorical, scientific and aesthetic values to them: The study discusses Quranic terms as well. The study includes, after the introduction, a theoretical introductory chapter and three applied chapters. These chapters include the examined groups of temporal terms, spatial terms, and their auxiliary adverbs. The study closes by conclusion and the findings and recommendations.