防火 (fáng huǒ) literally means 'prevent fire' — combining 防 (fáng), meaning 'to prevent' or 'to guard against', and 火 (huǒ), meaning 'fire'. As a compound noun, it refers to the practice, systems, or measures designed to prevent fires from starting or spreading. It is commonly used in contexts related to safety regulations, building design, workplace protocols, and public education.

This term appears frequently in official signage (e.g., 防火通道 'fire exit'), technical documents (e.g., 防火材料 'fire-resistant material'), and everyday warnings (e.g., 注意防火 'Pay attention to fire prevention'). While it can occasionally function adjectivally (e.g., 防火门 'fire door'), its primary grammatical role is as a noun denoting the concept or activity of fire prevention itself — not the act of extinguishing an existing fire (that’s 灭火).