中 (zhòng) means 'to be affected by' or 'to suffer from', while 毒 (dú) means 'poison' or 'toxic substance'. Together, 中毒 literally means 'to be struck by poison' — hence 'to be poisoned'. It describes the physical condition resulting from ingesting, inhaling, or absorbing harmful substances like spoiled food, chemicals, or venom. In modern usage, it also extends metaphorically to addiction, especially in compounds like 网络中毒 (internet addiction) or 游戏中毒 (gaming addiction), where the 'poison' is a compulsive behavior.

The word is commonly used in medical contexts (e.g., food poisoning, drug overdose) and public health warnings. It can be transitive (e.g., 中毒了某种细菌) or intransitive (e.g., 他食物中毒了). Unlike many verbs, it rarely appears without the '了' particle in past-tense narrative contexts, emphasizing the onset of the condition.