But never take off a heartless lady! (4)
I believe the answer is:
only
'but' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for only that I've seen before include "Mere" , ". . . . the Lonely (sung by Roy Orbison)" , "Simply" , "Existing alone with no other, perhaps a child" , "See 6" .)