to sparkle; flash: a mind that scintillates with brilliance.
to twinkle, as the stars.
Electronics. (of a spot of light or image on a radar display) to shift rapidly around a mean position.
Physics. (of the amplitude, phase, or polarization of an electromagnetic wave) to fluctuate in a random manner. (of an energetic photon or particle) to produce a flash of light in a phosphor by striking it.