Izutsu's semantic theory distinguishes between basic and relational meanings. The basic meaning refers to the intrinsic meaning of a word, independent of context. The relational meaning, on the other hand, is the meaning a word acquires when placed within the lexical system of a text. Izutsu's method for identifying word meanings within a text involves paying attention to context, paradigmatic and syntagmatic relationships, semantic opposition, and semantic fields. This descriptive-analytical study examines the basic meanings of words related to sin. The findings indicate that these words did not originally signify sin in their basic sense; rather, they were included in the semantic field of sin because each word initially described an aspect of sin. An examination of pre-Islamic usage reveals that "الإثم" (al-ithm) referred to sin in various instances, "الجرم" (al-jurm) eferred to the severity of sin, "الجناح" (al-junah) did not generally mean sin, "الخطیئة" (al-khati’ah) referred to mistakes, "الذنب" (al-dhanb) referred to the consequence of sin, and "السَّیِّئَةُ" (as-sayi'ah) to ugliness and evil. Analyzing the relational meanings of sin-related words in the Quran based on Izutsu's principles shows that "الإثم" (al-ithm) refers to deliberate sins; "الجرم" (al-jurm), contrary to its legal usage, denotes internal and hidden sins; "الجناح" (al-junah) relates to sins connected to legal rules; "الخطیئة" (al-khati’ah) encompasses external, internal, minor, major, intentional, and accidental sins, and is forgivable; "الذنب" (al-dhanb) has a broad scope of application and generally signifies sin with serious consequences but is still forgivable; and "السَّیِّئَةُ" (as-sayi'ah) refers to external and internal, minor and major sins.