scintillantly,adv.|ˈsɪntɪləntlɪ| [f. scintillant a. + -ly2.] In a scintillating manner. 1900H. Harland Cardinal's Snuff-Box xix. 191 The..buildings stood out..the white marble, palely, scintillantly amethystine.1928A. L. Fleming Dwellers in Arctic Night 151 Flashes of light from the Aurora Borealis move scintillantly in the sky.