Ed Banks dead happy! (6)
I believe the answer is:
elated
'happy' is the definition.
(similar in meaning)
'ed banks dead' is the wordplay.
'banks' indicates putting letters inside (bank can mean to surround or border).
'dead' becomes 'late' (similar in meaning).
'ed' placed around 'late' is 'ELATED'.
(Other definitions for elated that I've seen before include "Overjoyed, really delighted" , "Intensely happy" , "Very pleased, quite high" , "Overjoyed, in high spirits" , "In an enraptured state" .)