Sawm is an Arabic word for fasting regulated by Islamic jurisprudence. In the terminology of Islamic law, Sawm means to abstain from eating, drinking, smoking and sexual activity during daylight hours. The observance of sawm during the Islamic holy month of Ramadan is one of the Five Pillars of Islam, but is not confined to that month.

Muslims who are physically or mentally unwell may be excused some of these, as may those who are under twelve years old, the very old, those who are pregnant, breast-feeding, menstruating, or travelling.

If an adult does not fast for the reasons mentioned above, they should try to make up the fast at a later date, or make a donation to the poor instead. Muslims do not only abstain from physical things during Ramadan. They are also expected to do their best to avoid evil thoughts and deeds as well.