Ekadasi in Sanskrit means eleven. ‘Eka’ means “one” and ‘dasi’ is the feminine form of the word “dasa”, which means “ten”. Ekadasi is thus the eleventh day of both the dark and light fortnight of each month. On these auspicious days, devotees fast from grains and beans, Anhydrous fast, which doesn't allow drinking water, is the most preferred way to fast on Ekadasi. Such fasts should be broken the next morning preferably with milk. If one can't keep an anhydrous fast on Ekadasi, they can have only fruits and vegetables, but no grains.
Ekadasi in Hindu Scriptures
This fast is not only said to remove sins and bad karma but also gain blessings and good karma. Lord Krishna says: "I shall remove all obstacles from his path of spiritual development and bestow upon him the perfection of life" if a person keeps regular and rigorous fast on Ekadasi. In the Garuda Purana, Lord Krishna names Ekadasi as one of the "five boats for the people who are drowning in the ocean of worldly existence", the others being Lord Vishnu, the Bhagavad-Gita, the Tulsi or holy basil, and the cow. In the Padma Purana, Lord Vishnu says: "Among all plants, the Tulsi is my favorite, among all months, Kartik, among all pilgrimages, Dwaraka, and among all days, Ekadasi is most beloved."