Archaic or biblical second-person singular form of the verb 'to be,' meaning 'you are.'
From Old English 'eart,' the second-person singular present of 'beon'/'wesan.' The 'e-' prefix in 'ewest' appears in Early Modern English texts, possibly influenced by dialectal forms.
This archaic form appears in the King James Bible and Shakespearean texts—it's grammatically precise and would have sounded formal and elevated, which is why it was reserved for solemn religious language.
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