ras

Ras or RAS may refer to:

Arts and media

RAAS, the renin–angiotensin system, a hormone system that regulates blood pressure
Recurrent aphthous stomatitis or canker sores
Renal artery stenosis, the narrowing of the renal arteries
Respiratory airway secretory cell, cells in humans and some other mammals that maintain airway health
Reticular activating system in the brain, regulating wakefulness
Retinoic acid syndrome, a complication of acute promyelocytic leukemia
Ras superfamily, a superfamily of signalling proteins
Ras subfamily, a family of signalling proteins

.ras, a SunOS raster format
RAS algorithm, an algorithm for iterative proportional fitting in economics
RAS supergroup or SAR supergroup, a plant clade
Recirculating aquaculture system, an aquarium system that filters water rather than requiring new water supplies
Registration, Admission and Status, a telephony protocol under H.323
Reliability, availability and serviceability of computer hardware
Remote access service, on a network
Reusable Asset Specification of software
Row Address Strobe in dynamic random-access memory
Russian Accounting Standards

Ras (fascism), a title for a regional leader in Ethiopia under fascist Italy
Ras (title), an Ethiopian aristocratic and court title, as in Ras Tafari
Ras cheese, a variety popular in Egypt
RAS syndrome, "redundant acronym syndrome" syndrome
Reasonable articulable suspicion, a burden of proof in the United States legal system
Rás Tailteann, an annual cycling race in Ireland
Stari Ras, a capital city of medieval Serbian state of Raška
Replenishment at sea, providing naval ships with supplies while at sea
Catepanate of Ras, province of the Byzantine Empire