Contrived paintings, one functionary's short of (10)
I believe the answer is:
artificial
'contrived' is the definition.
(synonyms)
'paintings one functionary's short of' is the wordplay.
'paintings' becomes 'art' (painting is a type of artwork).
'one' becomes 'I' (Roman numeral).
'functionary' becomes 'official' (someone with official functions).
'short' is a deletion indicator (to be short of something is to lack it).
'official' with 'of' taken out is 'ficial'.
'art'+'i'+'ficial'='ARTIFICIAL'
(Other definitions for artificial that I've seen before include "Contrived, false" , "Kiss of life" , "Assumed" , "Bogus" .)