晒太阳 (shài tài yáng) literally means 'to expose to the sun' — 晒 means 'to dry or expose to sunlight', 太阳 means 'sun'. Together, the phrase describes the common activity of sitting or lying in direct sunlight for warmth, relaxation, or health benefits (e.g., vitamin D synthesis). It’s a colloquial, everyday verb used mostly in informal spoken and written Chinese.

The phrase is typically used with people as subjects (e.g., 我们、老人、孩子), but can also describe animals or even objects like bedding (though context clarifies meaning). Unlike formal medical terms, 晒太阳 carries a warm, leisurely connotation — think of grandparents on a park bench, babies napping near windows, or cats stretched out on sunny floors. It implies passive, gentle exposure, not intense tanning or sunbathing for cosmetic purposes.