Flash (5)
'flash' is the definition.
(I know that glint is a type of flash)
This is the entire clue.
(Other definitions for glint that I've seen before include "A very brief flash of light" , "Give out small flashes of light" , "Flicker of light" , "Glittering flash" , "Reflect" .)
(Other definitions for mob that I've seen before include "Mafiosi" , "Rabble" , "Ugly crowd" , "An unruly or uncontrolled gang" , "Rowdy crowd" .)