Shape of cricket in London? (4)

I believe the answer is:

oval

I'm a little stuck... Click here to teach me more about this clue!

'shape' is the definition.
(I know that oval is a type of conic)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for oval that I've seen before include "London cricket ground" , "6D 5A [TUBE STATION]" , "Courageous" , "Where England regained the Ashes" , "Like eggs" .)

I've seen this clue in The Mirror.

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