Trouble had repelled lovely thing in bed (6)
I believe the answer is:
dahlia
'lovely thing in bed' is the definition.
I can't judge whether this defines the answer.
'trouble had repelled' is the wordplay.
'trouble' becomes 'ail' (synonyms).
'repelled' says the letters should be written in reverse.
'ail'+'had'='ailhad'
'ailhad' back-to-front is 'DAHLIA'.
Can you help me to learn more?
(Other definitions for dahlia that I've seen before include "Plant of the daisy family" , "Lia had a showy flower" , "Showy garden plant" , "Showy bloom" , "one in bed" .)