Adds water to the stew, perhaps? (4)
I believe the answer is:
wets
'adds water to' is the definition.
(to wet something is to add water to it)
'stew perhaps?' is the wordplay.
'perhaps?' indicates anagramming the letters (I've seen 'perhaps' mean this).
'stew' is an anagram of 'WETS'.
'the' acts as a link.
(Other definitions for wets that I've seen before include "Moistens" , "Applies moisture" .)