Distribute some just rewards (5)
I believe the answer is:
strew
'distribute' is the definition.
(I know that distribute is the is a more specific form of the action of strew.)
'some just rewards' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'STREW' can be found hidden inside 'just rewards'.
(Other definitions for strew that I've seen before include "Scatter loosely" , "Sprinkle" , "Scatter untidily" , "Scatter, spread around" .)