瘾
yǐn · HSK 7
addiction
🚬 疒 sickness radical + 隐 yin hidden = a hidden sickness; sounds like 隐 yin
The 疒 radical marks illness, and the 隐 component (yin, meaning hidden) supplies the sound. An addiction is a sickness you keep hidden, which ties the two parts to the meaning and the yǐn reading.
瘾 — sickness radical 疒 + 隐 (yǐn, hidden)
A semantic-phonetic compound. The 疒 radical marks illness or affliction, while 隐 'hidden' supplies the sound yǐn and hints at something concealed inside. Together they describe a hidden sickness — an addiction or craving that grips a person from within.