Viper is a term that primarily refers to a venomous snake of the family Viperidae, characterized by long, hollow fangs that can be folded back when not in use.
In slang usage, viper can mean:
1. A treacherous or malicious person
2. In jazz culture of the 1930s, it referred to marijuana smokers
3. The Dodge Viper, an American sports car
4. In military terminology, it can refer to certain types of aircraft