HAFIZ حافظ
Lit. “A Guardian.” or protector. (1) One of the name of God al-Hafiz. (2) A Governor, e.g. Hafizu ‘l-Bait: the guardian of the Makkan temple. (3) One who has committed the whole of the Qur’an to memory.
‘Usman relates that the Prophet said: “The best person amongst you is he who has learnt the Qur’an and teaches it. (Mishkat, book ivv. c. i.). In the east it is usual for blind men to commit the Qur’an to memory, and thus obtain the honorable distinction of Hafiz.

Based on Hughes, Dictionary of Islam