hadj(n = noun.cognition)haj, hajj - the fifth pillar of Islam is a pilgrimage to Mecca during the month of Dhu al-Hijja; at least once in a lifetime a Muslim is expected to make a religious journey to Mecca and the Kaaba; "for a Muslim the hajj is the ultimate act of worship"
The pilgrimage to Mecca, performed by Mohammedans. It is the duty of Moslems to make a journey to Mecca at least once ina lifetime, or if that is not possible, three journeys to one of the alternate sacred sites. [1913 Webster]