复发
fù fā · HSK 7
to relapse
🔁 复 = repeat/again + 发 = emit/break out → break out again = relapse
复 (fù) carries the sense of 'again/repeat' (same 复 as in 复习 review). 发 (fā) means 'emit, send out, break out' (as in 发烧 develop a fever). Together: an illness breaks out again — a recurrence or relapse.
发 — simplified form of 發; from 癶 (two feet) + 弓 (bow) + 殳 (weapon)
The traditional form 發 depicted shooting an arrow from a bow, with 癶 showing outstretched feet and 弓 the bow, giving the core sense of 'send out, discharge.' From this came extended meanings like 'issue, emit, develop.' The modern simplified 发 also absorbed 髮 (hair), so it now covers both 'to send out' and 'hair.'