Moisten (3)
(Other definitions for dampen that I've seen before include "Apply liquid!" , "Make slightly moist, or discourage" , "Moisten" , "get a bit wet" , "Make moist or depressed" .)
'moisten' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wet that I've seen before include "Rainy (weather)" , "Watery" , "Saturated with liquid" , "Soaked with liquid" , "Soaked with water" .)