Greeting of grand one, too (4,9)

I believe the answer is:

good afternoon

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'greeting' is the definition.
(good afternoon is a kind of greeting)

'of grand one too' is the wordplay.
'of grand one too' can be anagrammed to 'GOOD AFTERNOON'.
Though, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for good afternoon that I've seen before include "PM greeting" , "Words of salutation" .)

I've seen this clue in The Irish Independent.

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