See no good PM save on underwear (4,5)

I believe the answer is:

long johns

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'underwear' is the definition.
(I've seen this before)

'see no good pm save on' is the wordplay.
'see' becomes 'lo' (archaic exclamation meaning 'look!').
'no good' becomes 'ng' (abbreviation).
'pm save' becomes 'johns' (I can't explain this - if you can you should believe this answer much more).
'on' is a charade indicator (letters next to each other).
'lo'+'ng'+'johns'='LONG JOHNS'

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(Other definitions for long johns that I've seen before include "Old habits" , "warm clothing" , "So-called pirate's" , "Thermal underpants" , "Underpants with legs" .)

I've seen this clue in The Guardian.

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