A single pinny's hem covers the lady's skirt (9)

I believe the answer is:

periphery

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'skirt' is the definition.
(thesaurus)

'a single pinny's hem covers the lady's' is the wordplay.
'a' becomes 'per' (eg 'one a day' means 'one per day').
'single' becomes 'ip' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'hem' indicates one should take the final letters (hem can mean an edge of something).
'covers' indicates putting letters inside.
'the lady's' becomes 'her' (belonging to a lady).
The last letter of 'pinny' is 'y'.
'ip'+'y'='ipy'
'ipy' placed around 'her' is 'iphery'.
'per'+'iphery'='PERIPHERY'

Can you help me to learn more?

(Other definitions for periphery that I've seen before include "margin" , "Edge -- border" , "Surrounding region" .)

I've seen this clue in The Times.

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