All round, maybe, it's marginal (3)
I believe the answer is:
rim
'all round' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for rim that I've seen before include "Raised edge of a round object" , "Brim, edge" , "Circular outer edge" , "Edge, border" , "'Brim, lip (3)'" .)
