thy

Used as a modifier before a noun.

Of or pertaining to thee: possessive of the pronoun thou, second person singular. It is used in solemn and grave style. See thine.

Of thee, or belonging to thee; the more common form of thine, possessive case of thou; — used always attributively, and chiefly in the solemn or grave style, and in poetry. Thine is used in the predicate. See thine.

because.

That belongs to thee; the possessive form of thou.

your (informal); that belongs to you (singular).