Sadden, upset (6)
I believe the answer is:
dismay
I believe this clue is a double definition.
'sadden' is the first definition.
(I've seen this before)
'upset' is the second definition.
(dismay can mean to upset)
(Other definitions for dismay that I've seen before include "Fill with consternation" , "'Alarm, consternation (6)'" , "Alarm, distress" , "Affright" , "Horrified amazement" .)