Uneasy over Sun being changed (7)
I believe the answer is:
nervous
'uneasy' is the definition.
(I know that uneasy can be written as nervous)
'over sun being changed' is the wordplay.
'being changed' is an anagram indicator.
'over'+'sun'='oversun'
'oversun' is an anagram of 'NERVOUS'.
(Other definitions for nervous that I've seen before include "Jittery" , "Tense" , "Fidgety" , "in a stew" , "Anxious or apprehensive" .)