TOS

TOS may refer to:

General

• Terms of service, rules by which one must agree to abide by in order to use a service; unless in violation of consumer protection laws, such terms are usually legally binding

Chemistry

• Tosyl, a chemical compound
• TOS, an abbreviation for Gy's sampling theory, a theory about the sampling of materials

Entertainment

• title of show, a Broadway musical
• Star Trek: The Original Series, a 1960s science fiction television series
• Battlestar Galactica (1978 TV series), a 1970s science fiction television series
• The Objective Standard, an American journal on culture and politics written from the Objectivist perspective
• T.O.S: Terminate on Sight, a 2008 album by G-Unit

Medicine

• Thoracic outlet syndrome, a syndrome involving compression of the superior thoracic outlet, leading to the compression of the neurovascular bundle passing between the anterior scalene and middle scalene
• Toxic oil syndrome, the name given to a disease outbreak in Spain in 1981, which killed over 600 people

Organizations

• Oceanography Society, a non-profit society founded in 1988, based in Rockville, Maryland, U.S. and incorporated in the District of Columbia
• Theosophical Order of Service, an international organization founded in 1908 by Annie Besant, the second International President of the Theosophical Society
• Temple of Set, an initiatory occult society claiming to be the world's leading left-hand path religious organization; it professes Setian philosophy and magical practice
• Tennessee Ornithological Society
• Trucial Oman Scouts, The Trucial Oman Scouts was a paramilitary force that the British raised in 1951 as the Trucial Oman Levies, to serve in the Trucial States.

Other uses

• TOS-1, a Soviet thermobaric weapon system nicknamed 'Buratino'
• Tam o' Shanter (cap), a Scottish bonnet, worn in place of a beret by certain military units
• The Operating System, an operating system of the Atari ST range of computers
• Tornado outbreak sequence, an extended period of high tornadic activity in which nearly every day there is significant tornado activity (multiple unbroken outbreaks)
• Tromsø Airport, in the northern city of Tromsø, Norway
• Television Oita, a television station in Oita, Oita Prefecture, Japan