Down in second, moved up (6)
I believe the answer is:
morose
'down' is the definition.
(both can mean sad)
'second moved up' is the wordplay.
'second' becomes 'mo' (both are short periods of time).
'moved up' becomes 'rose' (eg rose up into the air).
'mo'+'rose'='MOROSE'
'in' is the link.
(Other definitions for morose that I've seen before include "dark" , "grouchy" , "Down in the dumps" , "Sullen and brooding" , "in a grumpy mood" .)