scintillation Syllabification: (scin·til·la·tion)Pronunciation: /ˌsin(t)lˈāSHən/Definition of scintillation noun a flash or sparkle of light. the process or state of emitting flashes of light. Physics a small flash of visible or ultraviolet light emitted by fluorescence in a phosphor when struck by a charged particle or high-energy photon. Astronomy the twinkling of the stars, caused by the earth’s atmosphere diffracting starlight unevenly. scintillation in other Oxford dictionaries Definition of scintillation in the British & World English dictionary