Sparkle from the top of general rubbish (7)
I believe the answer is:
glitter
'sparkle' is the definition.
(I know that sparkle can be written as glitter)
'top of general rubbish' is the wordplay.
'top of' says to take the initial letters.
'rubbish' becomes 'litter' (litter is a kind of rubbish).
The first letter of 'general' is 'g'.
'g'+'litter'='GLITTER'
'from the' acts as a link.
(Other definitions for glitter that I've seen before include "addition to Christmas card" , "Flashiness" , "Shine brightly, coldly" , "Twinkle" , "Gleam" .)