The word "咪咪" is formed through the process of reduplication, where the single syllable "咪" (mī), a mimetic character often evoking a soft or high-pitched sound, is simply repeated. This repetition creates a new, colloquial term whose meaning is inherently more affectionate, informal, or diminutive than the base syllable, commonly referring to a cat or, in certain contexts, functioning as a childish euphemism. The formation relies entirely on this phonetic doubling to establish its familiar and often onomatopoeic character.