SI is the International System of Units.
SI, Si, or si may also refer to:
Arts, entertainment, and media
Literature
- 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
Music
- Sí (Julieta Venegas album), released in 2003
- 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" (Gigliola Cinquetti song), the Italian entry to the Eurovision Song Contest 1974
- Si (Zaz song), 2013
- Sí, a 2013 Spanish album by Malú
- "Sì", a 1985 song released by Italian actress Carmen Russo
Other uses in arts, entertainment, and media
- Si (film), original title of the 2010 South Korean film Poetry
Enterprises and organisations
Computing
- Swiss Informatics Society, a Swiss organization of computer science educators, researchers, and professionals
- The SI, a former name of the American defense contractor Vencore
Education
- St. Ignatius College Preparatory, a Jesuit high school in San Francisco, California, US
- Silay Institute, a private college in the Philippines
Government
- Si, a South Korean administrative unit
- Survey of India, an Indian government agency responsible for managing geographical information
- Swedish Institute (Svenska institutet), a Swedish government agency which promotes Sweden abroad
Politics
- Sarekat Islam, a socio-political organization in Indonesia under Dutch colonial rule
- Catalan Solidarity for Independence, a Catalan political party
- Situationist International, an organization of social revolutionaries
- Socialist International, a worldwide organization of political parties
- Solidarity and Equality, an Argentine political party (Spanish: Solidaridad e Igualdad)
Transportation
- 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
Other enterprises and organizations
- Samahang Ilokano, a fraternity/sorority based in the Philippines
- SÍ Sørvágur, a Faroese sports association
- Society of Indexers, a professional society based in the UK
- Sports Interactive, a British computer games development company
People with the name
- Si (surname), a Chinese surname
- Si (given name)
Places
- Mount Si, a mountain in the U.S. state of Washington
- Province of Siena (postal code and vehicle registration plate code)
- Si County, Anhui, China
- Si River, in China
- Slovenia's ISO 3166-2 code
Science and technology
Biology and healthcare
- Smithsonian Institution (SI is its international code)
- 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
Chemistry
- si, a chemical descriptor; See prochirality
- Silicon, symbol Si, a chemical element
- Disulfur diiodide, empirical formula SI
Computing and Internet
- .si, the Internet country code top-level domain for Slovenia
- Shift In, an ASCII control character
- SI register, or source index, in X86 computer architecture
- Swarm intelligence, an artificial intelligence technique
- Synthetic intelligence, an alternate term for or a form of artificial intelligence
Motor vehicles
- Honda Civic Si, an automobile
- Spark-ignition engine, a type of internal combustion engine
Other uses in science and technology
- Signal integrity, electronic circuit tools and techniques that ensure electrical signals are of sufficient quality
- Sine integral, Si(x)
- Spectral interferometry, attosecond physics technique
Titles and ranks
- 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
Other uses
- Statutory instrument (UK), abbreviated SI, the principal form in which delegated legislation is made in Great Britain
- Sì (dessert), a Chinese dessert
- Sídhe, Sí, or Sìth, Celtic mythological beings
- si, the Sinhala language ISO 639 alpha-2 code
- Supplemental instruction, an academic support program often used in higher education
See also
Topics referred to by the same term This disambiguation page lists articles associated with the title Si.If an internal link led you here, you may wish to change the link to point directly to the intended article. Category: