Troubled Delia's back (5)
I believe the answer is:
ailed
'troubled' is the definition.
('ail' can be a synonym of 'trouble')
'delia's back' is the wordplay.
'back' is a reversal indicator.
'delia' reversed gives 'AILED'.
(Other definitions for ailed that I've seen before include "Felt bad" , "Troubled" , "Was ill" , "Was unwell" , "was giving trouble" .)