Letters from Brother Aldhelm deceived goddess (4)
I believe the answer is:
hera
'goddess' is the definition.
(Greek goddess)
'letters from brother aldhelm deceived' is the wordplay.
'letters from' indicates the answer is hidden within the clue (a selection of letters from the clue).
'HERA' can be found hidden inside 'brother aldhelm deceived'.
(Other definitions for hera that I've seen before include "Zeus's wife and sister" , "female Greek deity" , "Greek goddess" , "Divinity" , "Greek equivalent of Juno" .)