How do I access the THESAURUS from InCopy window which is opened from the InDesign page editor? <-- this is my question.
You can't access it from InDesign.
There's no such thing as the "InCopy window" in InDesign. There's the story editor, which is similar.
It is not possible to access the Thesaurus from InDesign.
The reason why is kind of a mystery.
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