What is thou meaning?

"Thou" is an archaic English pronoun that was used in place of "you" to address one person, particularly during the Middle English and Early Modern English periods. It is the second person singular subjective case, while its objective case is "thee". "Thou" was commonly used in literature, poetry, and religious texts, but it gradually fell out of use in the 17th century as "you" became the more common pronoun for addressing both singular and plural. Today, the use of "thou" is considered archaic and formal, and is mostly used in religious or poetic contexts or as a deliberate attempt to evoke a historical or mythological tone.