Make more powerful, with "up" (4)
I believe the answer is:
soup
'make more powerful with up' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for soup that I've seen before include "Opus (anag) - typical starter" , "Stolen plate melted down" , "Liquid dish" , "Eskimo people" , "Cock-a-leekie, for example" .)