Cut crude arrangement with Spain (6)
I believe the answer is:
reduce
'cut' is the definition.
(I know that cut can be written as reduce)
'crude arrangement with spain' is the wordplay.
'arrangement with' indicates anagramming the letters.
'spain' becomes 'e' (abbreviation for Espana).
'crude' anagrammed with 'e' gives 'REDUCE'.
(Other definitions for reduce that I've seen before include "'Cut down, abridge (6)'" , "Lower" , "Cut down on,lessen" , "Concentrate" , "subdue" .)