French cultural organisation withdraw Monet's one artwork (6)
I believe the answer is:
fresco
'artwork' is the definition.
(I've seen this before)
'french cultural organisation withdraw monet's one' is the wordplay.
'french' becomes 'fr' (abbreviation).
'cultural organisation' becomes 'UNESCO' (UN cultural organisation).
'withdraw' indicates named letters should be taken away.
'monet's one' becomes 'un' ('one' in French - eg for Claude Monet).
'unesco' with 'un' removed is 'esco'.
'fr'+'esco'='FRESCO'
(Other definitions for fresco that I've seen before include "Picture painted on wall or ceiling before plaster is dry" , "Painting style" , "Painting done in wet plaster" , "Artistic work" , "Mural painted on wet plaster" .)