One takes a little bite, aftertaste coming back (4)
I believe the answer is:
gnat
'one takes a little bite' is the definition.
(gnats might bite you)
'aftertaste coming back' is the wordplay.
'aftertaste' becomes 'tang' (tang can mean a taste).
'coming back' says the letters should be written in reverse.
'tang' written backwards gives 'GNAT'.
(Other definitions for gnat that I've seen before include "Tiny thing" , "Small biting flying insect" , "Midge, mosquito" , "Small biting fly" , "Something that bites" .)