Rocks about going over eastern France (4)
I believe the answer is:
reef
'rocks' is the definition.
(I've seen this before)
'about going over eastern france' is the wordplay.
'about' becomes 're' (regarding**).
'going over' is a charade indicator (letters next to each other).
'eastern' becomes 'e'.
'france' becomes 'f'.
're'+'e'+'f'='REEF'
(Other definitions for reef that I've seen before include "Marine formation" , "endangered habitat" , "Chain of rocks underwater" , "Rocks in shallow water - kind of knot" , "Submerged ridge of rock or coral near the surface" .)