係 Simplified: 系 On the HSK 3 vocabulary list, at CEFR level B1. xì ㄒㄧˋ to connect to relate to to tie up to bind to be (literary) 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