What does tu est mon cheri mean in English?

"Tu est mon chéri" is grammatically incorrect in French. The correct phrase would be "Tu es mon chéri."

"Tu es mon chéri" translates to "You are my darling" or "You are my sweetheart" in English.

This phrase is a very affectionate and romantic way to address someone you love. It implies a strong emotional connection and a sense of endearment.