Comes to light or rises to the top (8)
I believe the answer is:
surfaces
'comes to light or rises to the top' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for surfaces that I've seen before include "Comes to light or rises to the top" , "planes - with 23a" , "transpires" , "They have length and breadth only" , "The outsides of objects" .)