Area of frozen water? Heading away from edge (4)
I believe the answer is:
rink
'area of frozen water?' is the definition.
(an ice rink)
'heading away from edge' is the wordplay.
'heading away from' means to remove the first letter.
'edge' becomes 'brink' (brink is a kind of edge).
'brink' with its initial letter removed is 'RINK'.
(Other definitions for rink that I've seen before include "Ice hockey pitch" , "Ice-skating venue" , "Area or arena for skating" , "Ice-skating arena" , "frozen surface" .)