Yet visitor represented glassiness? (10)

I believe the answer is:

vitreosity

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'glassiness?' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's an association between them I don't understand?

'yet visitor represented' is the wordplay.
'represented' is an anagram indicator.
'yet'+'visitor'='yetvisitor'
'yetvisitor' anagrammed gives 'VITREOSITY'.

Can you help me to learn more?

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

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