母子 On the HSK 6 vocabulary list, at CEFR level C2. mǔzǐ ㄇㄨˇ ㄗˇ mother and child parent and subsidiary (companies) principal and interest Sources CC-CEDICT, CC BY-SA 4.0 pinyinjs, Apache-2.0 国际中文教育中文水平等级标准, 中华人民共和国教育部, MIT