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Si

//siː// adj, name, noun, slang

Definitions

Adjective
  1. 1
    Initialism of sacroiliac. abbreviation, alt-of, initialism, not-comparable

    "SI joint"

Proper Noun
  1. 1
    International System of Units

    "The reason for the change to the International System of Measurement (SI) units was that over time the prototype lost atoms and therefore mass because it is “susceptible to damage and environmental factors,” according to the National Physical Laboratory (NPL), which houses Kilo 18, Britain’s copy of Le Grand K."

  2. 2
    Initialism of Smithsonian Institution. abbreviation, alt-of, initialism
  3. 3
    A diminutive of the male given name Simon.
  4. 4
    A river in Shandong, China.
  5. 5
    Alternative form of Xi. alt-of, alternative
Show 4 more definitions
  1. 6
    Initialism of Sports Illustrated. abbreviation, alt-of, initialism

    "“We have said from the start that our top priorities are to keep Sports Illustrated alive, uphold the legacy of the institution and protect our union jobs. We look forward to discussing a future with Minute Media that does that,” Emma Baccellieri, staff writer for SI and vice chair for the SI Union, said in a statement."

  2. 7
    A diminutive of the male given name Silas.
  3. 8
    A county of Suzhou, Anhui, China.

    "Dong Xuefeng, head of the Huangwei Township Central School in Sixian County, Anhui province, told a school gathering on Monday that Christmas was a disgrace to the Chinese people because of past humiliations inflicted on the nation by mostly Christian invaders."

  4. 9
    Various prefectures of imperial China. historical
Noun
  1. 1
    Initialism of signal integrity. abbreviation, alt-of, countable, initialism, uncountable
  2. 2
    A syllable used in solfège to represent the seventh note of a major scale.
  3. 3
    the syllable naming the seventh (subtonic) note of any musical scale in solmization wordnet
  4. 4
    Initialism of systems integration. abbreviation, alt-of, countable, initialism, uncountable
  5. 5
    a complete metric system of units of measurement for scientists; fundamental quantities are length (meter) and mass (kilogram) and time (second) and electric current (ampere) and temperature (kelvin) and amount of matter (mole) and luminous intensity (candela) wordnet
Show 14 more definitions
  1. 6
    Initialism of self-injury. abbreviation, alt-of, countable, initialism, uncountable
  2. 7
    a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors wordnet
  3. 8
    Initialism of suicidal ideation. abbreviation, alt-of, countable, initialism, uncountable
  4. 9
    Initialism of self-insertion (of the author into fan fiction). abbreviation, alt-of, countable, initialism, slang, uncountable
  5. 10
    Initialism of spark ignition. abbreviation, alt-of, countable, initialism, uncountable
  6. 11
    Initialism of supporting information. abbreviation, alt-of, countable, initialism, uncountable
  7. 12
    Initialism of special intelligence. abbreviation, alt-of, countable, initialism, uncountable
  8. 13
    Initialism of systematic internaliser. abbreviation, alt-of, countable, initialism, uncountable
  9. 14
    Initialism of swarm intelligence. abbreviation, alt-of, countable, initialism, uncountable
  10. 15
    Initialism of synthetic intelligence. abbreviation, alt-of, countable, initialism, uncountable
  11. 16
    Initialism of sales invoice. Philippines, abbreviation, alt-of, countable, initialism, uncountable
  12. 17
    Initialism of statutory instrument. Australia, Canada, UK, abbreviation, alt-of, countable, initialism, uncountable

    "The scope of SIs varies greatly, from the technical (e.g. to set or vary the dates on which different provisions of an Act will come into force, to change the levels of fines or penalties for offences or to make consequential and transitional provisions) to the much wider-ranging, such as filling out the broad provisions in Acts."

  13. 18
    Initialism of subinspector (of police, etc). abbreviation, alt-of, countable, initialism, uncountable

    "India's first transgender SI"

  14. 19
    Initialism of surface interval. abbreviation, alt-of, countable, initialism, uncountable

Etymology

Etymology 1

Borrowed from French SI (“Système international d'unités”).

Etymology 2

From Middle English si (“seventh degree or note of Guido of Arezzo's hexachordal scales”), Italian si in the solmization of Guido of Arezzo, from the initials of Latin Sāncte Iohannēs (“Saint John (the Baptist)”) in the lyrics of the scale-ascending hymn Ut queant laxis by Paulus Deacon; thus, also an initialism of Sāncte Iohannēs.

Etymology 3

From clipping of various words beginning with the syllable /saɪ/.

Etymology 4

From the Hanyu Pinyin romanization of the Mandarin 泗 (Sì) and Mandarin 肆 (Sì).

See also for "si"

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