Possibly alerts to changes (6)
I believe the answer is:
alters
'changes' is the definition.
(I know this)
'possibly alerts' is the wordplay.
'possibly' is an anagram indicator.
'alerts' is an anagram of 'ALTERS'.
'to' is the link.
(Other definitions for alters that I've seen before include "Changes to staler state" , "Changes, modifies" , "Changes, makes different" .)