Tat tvam asi means
Appearance
Sri Caitanya-caritamrta
CC Adi-lila
Tat tvam asi means "you are the same spiritual identity."
CC Adi 7.129, Translation and Purport: “It is the purpose of the Supreme Personality of Godhead to present praṇava (oṁkāra) as the reservoir of all Vedic knowledge. The words "tat tvam asi" are only a partial explanation of the Vedic knowledge.
Tat tvam asi means "you are the same spiritual identity."