Possessive form of thou: that which belongs to thee; which belongs to you (singular).
"The prayer began by addressing Thy name as holy and reverent."
Honorific alternative letter-case form of thy, sometimes used when referring to God or another important figure who is understood from context.
Only used in for thy, for-thy, which is an alternative form of forthy (“because, therefore”)
"The old manuscript was written entirely in archaic dialect, so I had to decipher phrases like "for thy lack of effort.""
Thy is a shortened form of the Middle English word þin, which traces its roots back to Old English and ultimately to the Proto-Indo-European word for "you." This archaic possessive pronoun entered modern usage as a contraction that has since fallen out of common speech.