Bottoms of wine barrels (5)
I believe the answer is:
dregs
'bottoms of wine barrels' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dregs that I've seen before include "Dross" , "Sediment, lees" , "Leftover drink, sediment" , "Sediment - rabble" , "Sediment at the bottom of a liquid" .)