'妒火' literally means 'jealousy fire' — a vivid metaphor combining 妒 (dù, 'jealousy') and 火 (huǒ, 'fire') to convey jealousy as an intense, burning, consuming emotion. Unlike neutral terms like 'jealousy' in English, this compound evokes heat, agitation, and potential destructiveness — as if the feeling itself is a raging flame inside the person.

It’s commonly used in literary, dramatic, or emotionally charged contexts — in novels, films, or passionate speech — to emphasize how overwhelming and painful jealousy can feel. While not everyday conversational vocabulary, it appears frequently in written Chinese and formal speech when describing deep emotional turmoil. The imagery reflects a long-standing cultural association of strong negative emotions with physical heat, similar to expressions like 'heartburn' in English but far more intense.