Grand girl, typically transparent (5)

I believe the answer is:

glass

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'typically transparent' is the definition.
I can't tell whether this definition defines the answer.

'grand girl' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'girl' becomes 'lass' (lass can informally mean a girl).
'g'+'lass'='GLASS'

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(Other definitions for glass that I've seen before include "such as one might hold at party" , "(Material used in) mirror" , "Watch-face cover" , "Telescope perhaps" , "measure of wine" .)

I've seen this clue in the Evening Standard.

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