助眠 (zhù mián) literally means 'to assist sleep' — 助 (zhù) means 'to help' or 'to aid', and 眠 (mián) means 'sleep'. Together, they form a compound noun meaning 'sleep aid': any substance, device, practice, or method intended to help people fall asleep faster or improve sleep quality. It is commonly used in medical, wellness, and consumer product contexts — for example, herbal teas, melatonin supplements, white-noise machines, or prescribed medications.

This term is neutral and formal, frequently appearing on health-related websites, pharmacy labels, and doctor’s advice. Unlike colloquial expressions like '睡不着怎么办' ('What should I do if I can’t sleep?'), 助眠 carries a clinical or solution-oriented tone, implying intentional support for healthy sleep physiology rather than just temporary relief.