Puts down? (7)
(Other definitions for saddens that I've seen before include "Distresses" , "Makes unhappy" , "Makes melancholy" .)
'puts down' is the definition.
('lay' can be a synonym of 'put down')
This is all the clue.
(Other definitions for lays that I've seen before include "Puts down the old ballads" , "Minstrel's melodies" , "Old narrative songs or poems" , "Arranges" , "Places (bets?)" .)