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Meanings and definitions for SI
What does SI stand for? What does SI mean?
- The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system.
- Si (novel), a 2014 novel by Bob Ong
- Sí (Peruvian magazine), a magazine notable for its anti-corruption reporting
- Skeptical Inquirer, an American magazine covering topics on science and skepticism
- Sports Illustrated, an American sports magazine
- Sí (album), a Spanish album by Mexican singer and songwriter Julieta Venegas
- Sì (Andrea Bocelli album), released in 2018
- "Sí" (Martin Jensen song), a 2015 song
- Si (musical note), the seventh note in the traditional fixed do solfège
- Sì (operetta), an operetta by the Italian composer Pietro Mascagni
- "Sì" (song), the name of the Italian entry to the Eurovision Song Contest 1974
- Sí, a 2013 Spanish album by Malú
- "Sì", a 1985 song released by Italian actress Carmen Russo
- Si (film), original title of the 2010 South Korean film Poetry
- Swiss Informatics Society, a Swiss organization of computer science educators, researchers, and professionals
- The SI, a former name of the American defense contractor Vencore
- St. Ignatius College Preparatory, a Jesuit high school in San Francisco, California, US
- Silay Institute, a private college in the Philippines
- Si, a South Korean administrative unit
- Smithsonian Institution, a U.S. government educational and research institute (website si.edu)
- Survey of India, an Indian government agency responsible for managing geographical information about India
- Swedish Institute (Svenska institutet), a Swedish government agency which promotes Sweden abroad
- Catalan Solidarity for Independence, a pro-independence Catalan political party
- Situationist International, a left-wing organisation
- Socialist International, a worldwide organization of democratic socialist and labour political parties
- Solidarity and Equality, an Argentine political party (Spanish: Solidaridad e Igualdad)
- Blue Islands (IATA airline code, SI)
- Skynet Airlines (IATA airline code SI, ceased operating 2004)
- Spokane International Railroad (reporting mark SI), a former railway in Washington, US
- Samahang Ilokano, a fraternity/sorority based in the Philippines
- SÍ Sørvágur, a Faroese sports association
- Sports Interactive, a British computer games development company
- Si (surname), a Chinese surname
- Si Robertson (born 1948), cast member of Duck Dynasty and its spinoff Going Si-ral
- Simon (given name), abbreviated Si
- Mount Si, a mountain in the U.S. state of Washington
- Province of Siena (two letter provincial designator), an Italian province
- Si County, county in Anhui, China
- Si River, a river in China
- Slovenia (ISO 3166-2), a country
- Sacroiliac, an anatomical abbreviation for the sacroiliac (joint)
- Self-injury, intentional, direct injuring
- Shock index, a measurement used to determine if a person is suffering shock
- si, a chemical descriptor; See Prochirality
- Silicon (Si), a chemical element
- .si, the Internet country code top-level domain for Slovenia
- Shift In, a control code in the C0 control code set
- SI register, or source index, in X86 computer architecture
- Swarm intelligence, an artificial intelligence technique
- Synthetic intelligence, an alternate term for or form of artificial intelligence
- Honda Civic Si, an automobile
- Spark-ignition engine, a type of internal combustion engine
- International System of Units (Système international d'unités, abbreviated SI), the modern international standard version of the metric system
- Signal integrity, electronic circuit tools and techniques that ensure electrical signals are of sufficient quality
- Sine integral, Si(x)
- Si, a Maghrebi Arabic variant of Sidi, a title of respect
- Si, a variant of the Thai honorific Sri
- Station inspector, a rank in the Singapore Police Force
- Sub-inspector, a rank in Indian Police forces
- Sì (dessert), a Chinese desert
- Sídhe or Si, Celtic mythological beings
- Sinhala language (ISO 639 alpha-2 code: si)
- Statutory Instrument, a form of delegated or secondary legislation
- Supplemental instruction, an academic support program often used in higher education
- S1 nuclease, an enzyme that digests singled-stranded DNA and RNA
- S1: Keep locked up, a safety phrase in chemistry
- Primary somatosensory cortex, also known as S1
- Tegafur/gimeracil/oteracil, also known as S-1, a chemotherapy medication
- S1 (Indian television station), a Hindi language television channel
- S1 (producer), a hip hop producer, member of the group Strange Fruit Project
- S1 No. 1 Style, a Japanese adult video company
- S-1 (Muay Thai), the championship of Thai boxing (Muay Thai)
- Gibson S-1, a guitar made by the Gibson Guitar Corporation
- Bill S-1, a pro forma bill in Canadian Parliament
- Form S-1, a U.S. Securities and Exchange Commission filling
- S-1 Executive Committee, a United States government entity during World War II
- S1 (military), an administrative position within military units
- ACPI S1 power state in computing
- Apple S1, integrated computer used in the Apple Watch
- Canon PowerShot S1 IS, a 2004 3.2 megapixel digital camera
- FinePix S1 Pro, a 2000 interchangeable lens digital single-lens reflex camera by Fujifilm
- Nikon Coolpix S1, a digital camera
- S1 Corporation, an American software development company
- S1 Core, a microprocessor-core
- S1 MP3 Player
- Samsung Galaxy S also commonly called S1 is a smartphone from 2010
- Sendo S1, a Sendo mobile phone model
- Siemens S1, a Siemens mobile phone
- Sony BDP-S1, a first generation Blu-ray Disc (BD) Player
- S1, an EPC in an LTE/4G network
- County Route S1 (California)
- FGC line S1, a suburban train line in Barcelona Province
- Line S1 (Milan suburban railway service)
- Line S1 (Nanjing Metro)
- Line S1 (Wenzhou Metro)
- S1 (Berlin), an S-Bahn line
- S1 (Dresden), an S-Bahn line
- S1 (Long Island bus)
- S1 (Munich), an S-Bahn line
- S1 (Rhine-Main S-Bahn), an S-Bahn line
- S1 (Rhine-Ruhr S-Bahn), an S-Bahn line
- S1 (Vienna), an S-Bahn line
- S1 line (Beijing Subway)
- S1 National Highway, a National Highways of Pakistan
- S1 Yingbin Expressway in Shanghai
- Stagecoach Gold bus route S1, in Oxfordshire, England
- Blackburn Buccaneer S.1 jet naval strike aircraft
- Focke-Wulf S 1, a German Focke-Wulf aircraft
- Fokker S.I, a 1919 Dutch primary trainer aircraft
- Hopfner S-1, a Hopfner aircraft
- Letov S-1, a 1920 Czechoslovak surveillance aircraft
- Loening S-1, a United States Army Air Service seaplane
- Loughead S-1 Sport 1920 US biplane
- Martinsyde S.1, a 1914 British biplane aircraft
- Pantsir-S1, a Russian anti-aircraft system
- Pitts S-1 aerobatic biplane
- S-1 Loening, a United States Army Air Service seaplane
- SSBS S1, a French experimental rocket
- Swift S-1, a 1991 Polish single seat aerobatic glider
- Audi S1, performance variant of Audi A1
- Invicta S1, a 2004 sports car
- S1 Scout Car, an armoured car built in Australia during the Second World War
- Superformance S1 Roadster, a Lotus Seven Type replicar produced in South Africa between 2001 and 2004, 56 vehicles were produced
- Alco S-1, a locomotive
- PRR S1, a duplex locomotive developed by the Pennsylvania Railroad
- USS S-1 (SS-105), a 1918 United States Navy experimental submarine
- a postcode covering Sheffield City Centre
- in human anatomy it can refer to either:
- the first sacral vertebra
- the sacral spinal nerve 1 of the vertebral column
- the primary somatosensory cortex in the brain
- Senior 1, the First Year in the Scottish secondary education system
- season one (of a television series)
- the Comet Ikeya-Seki, C/1965 S1
- the Upplands regemente (signal), a 1902 Signal Regiment of the Swedish Armed Forces
- a planned Bremen S-Bahn line
- a Hamburg S-Bahn line
- a Hanover S-Bahn line
- a Nuremberg S-Bahn line
- a RheinNeckar S-Bahn line
- a Rhein-Ruhr S-Bahn line
- a Rhine-Main S-Bahn line
- a Rostock S-Bahn line
- a Stuttgart S-Bahn line
- a Stadtbahn Karlsruhe line
- a star catalogue
- S1 (heart sound), a heart sound in cardiac auscultation
- S1, the n-sphere in two dimensions i.e. a circle
- S1, the one-dimensional sphere, or a circle
- Inverse second (s−1), a unit of frequency
- Akai S01, an Akai synthesizer
- ATC code S01 Ophthalmologicals, a subgroup of the Anatomical Therapeutic Chemical Classification System
- HMS Porpoise (S01), a 1956 Porpoise-class submarine of the Royal Navy
- MULTI-S01, an encryption algorithm based on a pseudorandom number generator
- Salt Institute
- Self Injury
- Silicon, Chemical element
- Slovenia, (705) ISO 2-letter country code
- Source Index
- Staten Island
- Status Indicator
- Supplementary Information, additional material to articles of Nature, published online by the NPG
- Systeme Internationale
- System Information
- System Integrater
- Sports Illustrated , Magazine
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