Sawm (Arabic: صوم‎) is an Arabic word for fasting regulated by Islamic jurisprudence. In the terminology of Islamic law, sawm means to abstain from eating, drinking (including water), having sex and anything against Islamic law (Ithm). 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.

Ṣawm is derived from Syriac: ܨܘܡܐ ṣawmā. Literally, it means "to abstain", cognates to Hebrew tsom.

For example, the Muslims of Central Asia, Afghanistan, India, Iran, Bangladesh, and Pakistan use the word uraza/rozah/roza/roja which comes from Persian. In Turkey, Sawm is called oruç (compare Kyrgyz öröz), while the Malay community in Malaysia, Brunei and Singapore call it puasa, which is derived from Sanskrit, upvaasa. Puasa is also used in Indonesia, Southern Thailand and Southern Philippines.

Muslims are prohibited from some things which are legal and natural for seeking the face of Allah. Muslims are prohibited from eating, drinking, smoking, and engaging in sexual intercource from dawn (fajr) to sunset (maghrib). Fasting is essentially an attempt to seek nearness to Allah and increase one's piety. One of the remote aims of fasting is to sympathize with those less fortunate ones who do not always have food and drink readily available. Also one must try to avoid cursing and thinking evil thoughts. Fasting is also viewed as a means of controlling one's desires (of hunger, thirst, sexuality, anger) and focusing more on devoting oneself to God.