Would an ace do so faultlessly? (5)

I believe the answer is:

serve

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'would' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for serve that I've seen before include "Attend; start to play tennis" , "Open play at tennis" , "get game started" , "Deliver" , "Opening shot at tennis" .)

I've seen this clue in the Evening Standard.

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