Avoid giving the Spanish due treatment (5)
I believe the answer is:
elude
'avoid' is the definition.
(I know that elude is a type of avoid)
'giving the spanish due treatment' is the wordplay.
'giving' says to put letters next to each other.
'the spanish' becomes 'el' ('the' in Spanish).
'treatment' indicates an anagram (letters treated or processed differently).
'due' with letters rearranged gives 'ude'.
'el' next to 'ude' is 'ELUDE'.
(Other definitions for elude that I've seen before include "Escape by stratagem" , "Escape adroitly" , "Dodge, duck" , "Get round" , "Puzzle" .)