Complained about having been barred (6)
I believe the answer is:
railed
'barred' is the definition.
(thesaurus)
'complained about having been' is the wordplay.
'complained about' becomes 'rai' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'having' says to put letters next to each other.
'been' becomes 'led' (leading is a kind of being).
'rai'+'led'='RAILED'
Can you help me to learn more?
(Other definitions for railed that I've seen before include "Complained angrily, being barred" , "Complained bitterly, being barred" , "Complained loudly,being barred" , "Complained or protested strongly" , "Complained strongly, being barred" .)