阴性
yīn xìng · HSK 7
feminine
阴 (yin, the shadowy/negative side) + 性 (nature, gender) = negative result or feminine gender
阴 is the yin of yin-yang, the dark/negative pole; 性 means nature or sex. Together: a negative (阴性) test result, or the feminine grammatical gender. Contrast with 阳性 (yang + nature), which means positive or masculine.
阴 — left 阝(mound) + 月 (moon)
Originally written 陰, combining the 'mound/hill' radical 阝 with 侌 (clouds covering the sun), suggesting the shaded north side of a hill. The simplified form 阴 replaces the phonetic with 月 (moon), reinforcing the idea of darkness, shadow, and the feminine yin principle opposed to 阳 (yang).
性 — heart radical 忄 + 生 (life/birth)
性 is a semantic-phonetic compound. The heart radical 忄 supplies the meaning, pointing to inner feelings or innate qualities, while 生 ('birth, life') gives the sound and hints at what one is born with. It originally meant 'inborn nature' and later extended to 'character,' 'gender,' and 'sex.'