Scan a red construction (4)
I believe the answer is:
read
'scan' is the definition.
(synonyms)
'a red construction' is the wordplay.
'construction' is an anagram indicator (answer constructed from certain letters).
'a'+'red'='ared'
'ared' with letters rearranged gives 'READ'.
(Other definitions for read that I've seen before include "Study (for a degree?)" , "Use a book" , "examined" , "register" , "Run one's eye over" .)