from
The Collaborative International Dictionary of English v.0.48
Thyself \Thy*self"\, pron.
An emphasized form of the personal pronoun of the second
person; -- used as a subject commonly with thou; as, thou
thyself shalt go; that is, thou shalt go, and no other. It is
sometimes used, especially in the predicate, without thou,
and in the nominative as well as in the objective case.
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Thyself shalt see the act. --Shak.
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Ere I do thee, thou to thyself wast cruel. --Milton.
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