'Snake venom' (shé dú) is a toxic substance produced by certain snakes, primarily used for hunting prey or self-defense. The word is a compound noun formed by two characters: 蛇 (shé), meaning 'snake', and 毒 (dú), meaning 'poison' or 'toxin'. Together, they literally mean 'snake poison', and the term is used exclusively in scientific, medical, and general descriptive contexts when referring to the biologically active secretion from snake venom glands.

This word appears frequently in discussions about wildlife biology, emergency medicine, antivenom development, and traditional Chinese medicine (where processed snake venom is occasionally used in controlled formulations). Unlike the more general term 毒 (dú), which can refer to any kind of poison, 蛇毒 specifically denotes venom derived from snakes — not from spiders, scorpions, or other venomous animals. It is always treated as an uncountable noun in Chinese and does not take measure words like 个 or 些 in standard usage.