The word 阴性 (yīnxìng) is a compound term formed through morphological derivation in Chinese, where the root character 阴 (yīn), which fundamentally carries meanings of "shade", "dark", "feminine", or "negative" (as in yin-yang philosophy), is combined with the suffix 性 (xìng), meaning "nature", "quality", or "-ity". This structure follows a common pattern in modern Chinese where 性 nominalizes an adjective, creating an abstract noun meaning "the quality of being yin". In contemporary usage, this semantic base has been extended into specific technical domains: in medicine, it denotes a "negative" test result (e.g., for a pathogen), and in grammar, it indicates "feminine" gender, both applications deriving from the core concept of a passive, receptive, or negative principle associated with 阴.