'半岛' (bàn dǎo) literally means 'half island' — combining 半 (bàn), meaning 'half', and 岛 (dǎo), meaning 'island'. It refers to a piece of land that is surrounded by water on three sides but connected to a larger landmass on the fourth, just like its English counterpart 'peninsula'. This term is purely geographical and carries no emotional or cultural connotation beyond physical description.

The word is commonly used in geography textbooks, news reports about regional weather or geopolitics, travel writing, and maps. It appears in proper nouns such as 韩国 (South Korea), which lies on the Korean Peninsula (朝鲜半岛 Cháoxiǎn Bàndǎo), or 山东半岛 (Shāndōng Bàndǎo), a well-known peninsula in eastern China. Unlike colloquial terms, 半岛 is neutral and formal, rarely used in casual speech unless discussing location or terrain.