Chinese words · HSK 7–9

函

hán

letter; correspondence

Every meaning

hán

  1. (math.) function (short for 函数)
  2. (bound form) case; box
  3. (bound form) letter; correspondence

Meanings are from Mandarin The Wild’s own dictionary. Levels follow the official HSK word list (the exam’s 2025 syllabus, levels 7–9 shown together).