The lexical definition of the classical Arabic verb rajaba is "to respect",[1] which could also mean "be awe or be in fear", of which Rajab is a derivative.
[1] Muslims believe Rajab is the month in which ‘Alī ibn Abī Tālib, the first Shia Imam and the fourth Rashidun caliph, was born.
Rajab is also the month during which Isra and Mi'raj (Muhammad's journey from Mecca to Jerusalem and then through the seven Heavens) took place.
There are two important events during the month, namely the birthday of Ali ibn Abi Talib and Muhammad's first revelation in Shia tradition.
The estimated start and end dates for Rajab, based on the Umm al-Qura of Saudi Arabia, are:[2]