Record description (3-4)
I believe the answer is:
all-time
'record description' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for all-time that I've seen before include "Unsurpassed to date" , "As yet unsurpassed" , "So far unsurpassed" , "Best ever" , "Hitherto unsurpassed" .)