Si

Si, si, or SI may stand for: Template:Wiktionarypar3

'SI', the Système International d'Unités (the 'metric' International System of Units)
one of two Spanish words pronounced like "see":
- sí (accented) for "yes" and
- si (unaccented) for "if"
a French word pronounced like "see" meaning "yes, on the contrary", "as," "however," "so," and "if."
in music, Si, the seventh note of solfege
in chemistry, Si, the chemical symbol for silicon
in Mohican mythology, Si, the lunar deity
Station Inspector the highest non-commissioned officer rank in the Singapore Police Force.
Sinhalese language, (ISO 639 alpha-2)
Slovenia (ISO 3166-1 alpha-2 country code, SI)
in British law, a Statutory Instrument
Smithsonian Institution
Socialist International
Spokane International Railroad Template:Reporting mark
Sports Illustrated
Sports Interactive
Signal Integrity
Situationist International
Staten Island, a borough of New York City and an island in the Hudson River
Swedish Institute (Svenska institutet)
System integrator
Supplemental Instruction
Sexual Intercourse (medical abbreviation, not common usage)
Self-injury or self-harm
SI is the acronym for Swarm Intelligence
In mathematics, si or Si is the Sine integral
the IATA code for Skynet Airlines
The Si is a self-replicating artifact in the roguelike game Ancient Domains of Mystery
The Si designation is used by Honda to denote high-performance variants of models they manufacture
The Shift in control code in the C0 control code set.