True lady undone in this? (8)
I believe the answer is:
adultery
'this?' is the definition.
The definition suggests a singular noun which matches the answer.
'true lady undone' is the wordplay.
'undone' indicates anagramming the letters.
'true'+'lady'='truelady'
'truelady' with letters rearranged gives 'ADULTERY'.
'in' is the link.
Can you help me to learn more?
(Other definitions for adultery that I've seen before include "Marital infidelity - try a duel (anag)" , "The act of marital infidelity" , "form of betrayal" , "Moral lapse" , "frowned-on relations" .)