Small mark (4)
(Other definitions for fleck that I've seen before include "Streak or spot" , "Little spot" , "Speckle" , "A bit of colouring" , "Small patch of colour/light" .)
(Other definitions for spot that I've seen before include "jam > stain" , "See - speckle" , "moral flaw" , "Small mark or stain" , "Catch sight of - pimple" .)