Surface even changed with hesitation (6)
I believe the answer is:
veneer
'surface' is the definition.
(thesaurus)
'even changed with hesitation' is the wordplay.
'changed' indicates an anagram.
'with' is a charade indicator (letters next to each other).
'hesitation' becomes 'er' (sound made while hesitating - um, er).
'even' is an anagram of 'vene'.
'vene'+'er'='VENEER'
(Other definitions for veneer that I've seen before include "Thin wood facing" , "Face" , "Thin covering on top, as of wood" , "Thin layer of a fine material on the surface" , "A thin layer on the surface, often wood" .)