Had no success in a field of activity (6)
I believe the answer is:
failed
'had no success' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Maybe there's an association between them I don't understand?
'a field of activity' is the wordplay.
'of activity' indicates anagramming the letters (I've seen 'activity' mean this (letters become active)).
'a'+'field'='afield'
'afield' is an anagram of 'FAILED'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for failed that I've seen before include "Was unsuccessful, did not pass exam" , "Did not succeed, perhaps at exam" , "Didn't succeed" , "Didn't make it - not well" , "Bankrupt" .)