Volatile definition, evaporating rapidly; passing off readily in the form of vapor: Acetone is a volatile solvent. See more. Define volatile (adjective) and get synonyms. What is volatile (adjective)? volatile (adjective) meaning, pronunciation and more by Macmillan Dictionary. Meaning, pronunciation, example sentences, and more from Oxford Dictionaries. ' volatile solvents such as petroleum ether, hexane, and benzene'. Times, Sunday Times This man looks like a very volatile person. Computing designating or of memory that does not retain stored data when the power supply is disconnected. Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 10,, visitors served. Related Terms of 'volatile'.