- 不管三七二十一 bùguǎnsānqī'èrshíyī blindlyacting recklessly or impulsively based on a simplistic or hopelessly optimistic assumption
- 二十一点 èrshíyīdiǎn blackjackthe card game blackjack
- 三七二十一 sānqī'èrshíyī factsthe facts of the matter or the actual situation
- 二十一世纪 èrshíyīshìjì 21st century
- 二十一条 èrshíyī Tiáo Twenty-One Demandsthe Japanese Twenty-One Demands of 1915
- 管他三七二十一 guǎntāsānqī'èrshíyī regardlessacting impulsively or without considering the consequences; no matter what