Hebrew. (Lit. 'Master of Repentance'). A Jew who was raised outside the Orthodox tradition, who subsequently adopted Orthodox Jewish customs.
Often abbreviated BT ('bee tee'), especially when spoken.
Fem. form is ba'alas teshuvah (Ashkenaz) or ba'alat teshuva (Sephard).
Plural is ba'alei teshuva.
When Sam became a ba'al teshuvah, he started to observe the sabbath, and now he eats only kosher