Number, not name, in PM's familiar address (5)

I believe the answer is:

matey

'familiar address' is the definition.

I can't explain the rest of the clue.

(Other definitions for matey that I've seen before include "Close chum (slang)" , "Chummy" , "Pirate's chum (colloq.)" , "Friendly, sociable" , "Sunshine" .)

I've seen this clue in The Independent.

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