The word 虱子 (shīzi), meaning "louse", is formed through a common morphological process in Mandarin where a monosyllabic root (虱), which historically stood alone as the classical word for louse, is combined with the nominal suffix 子 (zi). This suffix, often used to form everyday concrete nouns, adds no independent meaning but creates a disyllabic word that fits the modern Chinese phonological preference for two-syllable words, thereby enhancing rhythm and clarity in speech while distinguishing it from homophones.