Superfluous, and under changes with time (9)
I believe the answer is:
redundant
'superfluous' is the definition.
('redundant' can be a synonym of 'superfluous')
'and under changes with time' is the wordplay.
'changes with' is an anagram indicator.
'time' becomes 't'.
'and'+'under'='andunder'
'andunder' mixed up with 't' can make 'REDUNDANT'.
(Other definitions for redundant that I've seen before include "on the scrap heap?" , "No longer required, unnecessary" , "Superfluous to requirements" , "jobless!" , "unwanted" .)