Pure lady loses one pound (8)
I believe the answer is:
virginal
'pure' is the definition.
(I know that pure can be written as virginal)
'lady loses one pound' is the wordplay.
I cannot quite understand how this works, but
'lady' could be 'virgina' and 'virgina' is present in the answer.
'pound' could be 'l' (the pound sign is based on an L) and 'l' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for virginal that I've seen before include "Untouched - smaller version of the harpsichord" , "Untouched - old keyboard instrument" , "in immaculate condition" , "Rectangular harpsichord" , "spotless" .)