Old nan has splendid morning (7)

I believe the answer is:

grandam

'old nan' is the definition.
(archaic term for a grandmother)

'splendid morning' is the wordplay.
'splendid' becomes 'grand' (both can mean impressive).
'morning' becomes 'am' (as in 12:00 AM).
'grand'+'am'='GRANDAM'

'has' acts as a link.

(Another definition for grandam that I've seen is " Experienced old woman".)

I've seen this clue in The Times.

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