Celebrated seat unexpectedly being held by Iron Duke (7)
I believe the answer is:
feasted
'celebrated' is the definition.
Although both the answer and definition are past participle verbs, I cannot see how they can define each other.
'seat unexpectedly being held by iron duke' is the wordplay.
'unexpectedly' is an anagram indicator.
'being held by' indicates putting letters inside.
'iron' becomes 'fe' (Fe is the chemical symbol for iron).
'duke' becomes 'd' (abbreviation).
'seat' anagrammed gives 'east'.
'east' inserted inside 'fe' is 'feaste'.
'feaste'+'d'='FEASTED'
Can you help me to learn more?
(Other definitions for feasted that I've seen before include "Ate high off the hog" , "Ate lavishly" , "Banqueted" , "Had a lot to eat" .)