"Thou/thee/thy" is an archaic English pronoun.
Thou/thee/thy is an archaic English pronoun. Its forms are thou (subject), thee (object), thy (possessive, dependent form), thine (possessive, independent form; also used as a possessive dependent form, usually before words starting with a vowel or "h"), and thyself (reflexive). By 1800, it was no longer in common use.