Zahra…. The Splendid!
As it was reported in v. 10 of Bihar al-Anwar, Ibn Abbas narrated that Allah’s Messenger said:
“Surely my daughter Fatima is: The Mistress of all women from the beginning to the end. She is part of me, and the light of my eyes, She is the flower of my heart, and is my soul, (Fatima) is a human huri, who whenever she stands in prayers in the presence of Her Lord (Exalted is His Name), her light illuminates the skies for the angels, like stars shine to people on Earth.”
This narration clarifies the reason for which Fatima az-Zahra (sa) was given the name Zahra. There are other narrations, which mention that she had a bright and splendid face.