GBS left something warm (5)

I believe the answer is:

shawl

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'something warm' is the definition.
I can't judge whether this definition defines the answer.

'gbs left' is the wordplay.
'gbs' becomes 'shaw' (I've seen this in another clue).
'left' becomes 'l' (common abbreviation).
'shaw'+'l'='SHAWL'

Can you help me to learn more?

(Other definitions for shawl that I've seen before include "Wrap for a baby" , "Cover for head and shoulders" , "Loose garment for head or shoulders" , "Baby wrapper" , "Female garment" .)

I've seen this clue in the Evening Standard.

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