Understanding the meaning of the word "Nohas" in verse35 of Surah Al-Rahman is an issue that can lead to the correct understanding of this verse in the context of the verses of the aforementioned Surah. Which include: smoke, molten copper(=molten metal), lead, oil residue, something with a strong wind, a fire with a strong wind, an extremely foul smell. On the other hand, in Persian and English translations, there is no single meaning of the word "Nohas" in the aforementioned verse; however, the scope of disagreement among translators in presenting the translation of this word isnot as wide and diverse as the opinions of commentators. Thus, after exploring the meaning of this word in the literature of the pre-Islamic period and the Mukhaddramin, it becomes clear that in the scope of "pre-Islamic literature", the word in question was used only in the meaning of "Nohas", and in the poems of the Mukhaddramin, it was used in both the meanings of "essence, nature, and character" and "copper metal. Gradually, the diversity and multiplicity of meanings in dictionary books has reached five paragraphs: "Smoke and fire","copper(=metal)","a certain amount remaining of something","nature and essence",and "the original value of each thing" which apparently has led to differences in the views of commentators and translators. The present study,by applying the library method and descriptive-analytical approach, based on the context of the verses and also utilizing the narrations of the Infallibles(S), finally suggests the meaning of molten copper(=molten metal) as the preferred meaning for this word.