What is the correct meaning of the the word "Rabb"? And is it derived from "tarbiyah" (upbringing) as some claim?

"Al-Rabb" (the Lord) is one of the names of Allah the Almighty, and it is not applied to anyone else except in a possessive construct. It has been said that it is the Greatest Name (al-Ism al-A'zam). Linguistically, it refers to the owner, the master, the reformer, the director, the sustainer, and the worshipped, and all these meanings are true concerning Allah the Almighty.