Run twice to say farewell (6)

I believe the answer is:

byebye

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'say farewell' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'run twice' is the wordplay.
'run' becomes 'bye' (type of cricket run).
'twice' shows that letters should be duplicated.
'bye' duplicated is 'BYEBYE'.

'to' acts as a link.

Can you help me to learn more?

I've seen this clue in The Daily Express.

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