瘾 (yǐn) specifically means 'addiction' — a compulsive physical or psychological dependence on a substance or activity (e.g., smoking, internet). It is stronger and more clinical than 嗜好 (shì hào), which can mean a strong hobby or indulgence but doesn't necessarily imply loss of control. 欲望 (yù wàng) is a general 'desire' without the compulsive or harmful sense.