“The Lord,” “The Sustainer,” “The supporter.” A title frequently used in the Qur’an for the Divine Being, e.g.:-
Surah iii. 44: “God (Allah) is my Lord (Rabb) and your Lord (Rabb).”
Surah xviii 13: “Our Lord (Rabb) is the Lord (Rabb) of the heavens and the earth.”
From its frequent occurrence in the Qu’ran, it would seem to occupy the place of the Hebrew Jehovah, the of the LXX., the Dominus of the Vulgate, and the LORD of the English Bible; but all Muslim writers say that whilst Allah is the Ismu ‘z-Zat or “Essential name of God,” ar- Rabb, “the Lord,” is but, an Ismu Sifah, or attribute, of the Almighty.
Al-Baizawi, the commentator (p. 6, line 10, of Flugul’s edition), says, “rubb, in its literal meaning, is ‘to bring up,’ that is, to bring or educate anything up to its perfect standard, by slow degrees, and inasmuch as the Almighty is He who can bring everything to perfection, the ‘word الربar-Rabb, is especially applied to God.”
It is the Hebrew Rab, which enters into the composition of many names of dignity and office in the Bible.
In Muslim works of theology, the word occurs with the following combination:-
Rabbu ‘l-’Izzah…. Lord of Glory
Rabbu ‘l-’Alamin …. Lord of the Universe.
Rabbu ‘l-’Arbab …. Lord of Lords.
Rabbu ‘l-’Ibad …. Lord of (life) Servants
The word is also used for a master or owner, e.g.:-
Rabbu ‘d-Dar…. The Master of the house.
Rabbu ‘l-Arz…. A Landowner.
Rabbu ‘l-Mul…. A possessor of property.
Rabbu ‘s-Salaf…. A person who pays in advance for an article
Based on Hughes, Dictionary of Islam