Most delayed the French examination (6)
I believe the answer is:
latest
'most delayed' is the definition.
(I've seen this in another clue)
'the french examination' is the wordplay.
'the french' becomes 'la' ('the' in French).
'examination' becomes 'test' (synonyms).
'la'+'test'='LATEST'
(Other definitions for latest that I've seen before include "Most recent or most tardy" , "Most recent, hot off the press" , "Up-to-the-minute" , "State-of-the-art" , "Most recent report" .)