Dampen (7)
I believe the answer is:
moisten
'dampen' is the definition.
(I know that dampen can be written as moisten)
This is the entire clue.
(Other definitions for moisten that I've seen before include "contrary to sixteen down [DEHYDRATE]!" , "Add water - dampen" , "It's on me (anag)" , "water a bit" , "Make damp, say lips with tongue" .)