Make slightly wet (7)
I believe the answer is:
moisten
'make slightly wet' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for moisten that I've seen before include "It's on me (anag)" , "contrary to sixteen down [DEHYDRATE]!" , "water a bit" , "What one's eyes may do!" , "Make damp or slightly wet" .)