Shadow kept spreading beside burnt legs (8,7)

I believe the answer is:

designer stubble

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'shadow' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'spreading beside burnt legs' is the wordplay.
'spreading' indicates an anagram.
'beside'+'burnt'+'legs'='besideburntlegs'
'besideburntlegs' with letters rearranged gives 'DESIGNER STUBBLE'.

'kept' acts as a link.

Can you help me to learn more?

(Other definitions for designer stubble that I've seen before include "shave this?" , "kind of personal appearance" , "Fashionable unshaven look" .)

I've seen this clue in the Sydney Morning Herald.

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