Karadaiyan Nombu is a traditional Tamil Hindu fasting ritual performed by married women to pray for the health, happiness, and longevity of their husbands.

During this observance, women fast and offer prayers to Goddess Parvati, who is considered the embodiment of marital devotion and strength. The ritual includes the application of turmeric and kumkum on the body, tying sacred threads (karadai) around the wrist, and preparing special offerings such as sweet dishes and fruits. Women visit temples and participate in group prayers, reinforcing the communal aspect of this festival. The fast symbolizes purity, dedication, and the divine protection of marriage.