Crossword Genius

Roughly 66 per cent ultimately get this word wrong (3-6)

Ross

I believe the answer is:

two-thirds

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'roughly 66 per cent ultimately get this word wrong' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Maybe there's an association between them I don't understand?

'ultimately get this word wrong' is the wordplay.
'ultimately' indicates one should take the final letters.
'wrong' is an anagram indicator.
The final letter of 'get' is 't'.
'this'+'word'='thisword'
'thisword' with letters rearranged gives 'wothirds'.
't'+'wothirds'='TWO-THIRDS'

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