Painting of Manx cat turned up (3)
I believe the answer is:
oil
'painting' is the definition.
(oil painting is a kind of painting)
'of manx cat turned up' is the wordplay.
'of manx' means to remove the last letter (I've seen 'manx' mean this (Manx cats have no tail)).
'cat' becomes 'lion' (lion is a kind of cat).
'turned up' says the letters should be written in reverse.
'lion' with its last letter removed is 'lio'.
'lio' back-to-front is 'OIL'.
(Other definitions for oil that I've seen before include "Fossil fuel" , "Crude" , "Slippery liquid" , "Greasy liquid" , "Grease" .)