The word 婶婶 (shěnshen) is formed through a reduplication of the base character 婶 (shěn), which itself is a colloquial term for "father's younger brother's wife" or "aunt". This pattern of doubling a single-character kinship term is common in Chinese to express familiarity, affection, and respect. The reduplication softens the address, making it more intimate and endearing than the single character alone, similar to how "Mommy" functions in English compared to "Mom". Therefore, 婶婶 is the warm, everyday form of address for this specific aunt, distinct from the more formal written term 叔母 (shūmǔ).