Thy is an old-fashioned word for your. It is still used in some churches, for example, "Love Thy Neighbour!"
More specifically in Shakespearean/Elizabethan/King James era English, "thy" is the second person singular possessive pronoun. "Your" in contemporary English, of course, can mean either singular or plural, while in that era "your" would have been used exclusively for the plural. Similarly, the second person singular nominative is "thou" as opposed to the plural "ye." The second person singular objective is "thee" instead of the plural "you." First and third person pronouns remain unchanged.
The King James word "thy" means "your." ("Thy thy" wouldn't mean anything. I assume it's a typo.)
Watch what (not) to say?
It means that beauty comes from within the heart, not from how a person looks.
It means to give up your family and inheritence.
CONSIDER THY WAYS means THINK ABOUT WHAT YOU ARE DOING and WHAT YOUR MOTIVES ARE. Do they line up with the Word of God?
"Love Thy Neighbor" tattoos mean hate your brother before you hate your foe.
Follow your instincts.
It means boxes of stuff
It means a Vietnamese name for a girl.
Get out of my face..or leave..or get out of my sight
keep thy faith
I pledge my oath to you.
Thy Kingdom Come!