Scintillate (7)
I believe the answer is:
twinkle
'scintillate' is the definition.
(I know that scintillate can be written as twinkle)
This is the entire clue.
(Other definitions for twinkle that I've seen before include "Shine in flashes, like a star" , "Sparkle, gleam" , "Glitter like a star" , "''..., ... little star'' (song)" , "Shine flashingly" .)