That which troubles true lady? (8)
I believe the answer is:
'that which' is the definition.
I can't tell whether this definition defines the answer.
'troubles true lady?' is the wordplay.
'troubles' indicates anagramming the letters (I've seen 'trouble' mean this).
'truelady' is an anagram of 'ADULTERY'.
Can you help me to learn more?
(Other definitions for adultery that I've seen before include "form of betrayal" , "Extramarital affair" , "Unfaithfulness to one's spouse" , "excluding union involvement?" , "Betrayal of a partner" .)