隐患
yǐn huàn · HSK 7
a danger concealed within sth
💣 隐 hidden + 患 trouble = a hidden trouble, danger lurking out of sight
隐 means concealed or unseen; 患 means trouble, calamity, or affliction (the same 患 as in 患者 patient). Together they name a problem already present but not yet surfaced — a latent hazard like faulty wiring inside a wall.
患 — 串 chuàn (phonetic) + 心 heart
A semantic-phonetic compound: 心 'heart/mind' gives the meaning of inner worry, while 串 'string/skewer' suggests the sound. The original sense was anxiety or troubles weighing on the mind, which later extended to 'suffer from' an illness or calamity.