SI

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 Dictionary entry overview: What does SI mean? 

• SI (noun)
  The noun SI has 3 senses:

1. 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

2. 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)

3. the syllable naming the seventh (subtonic) note of any musical scale in solmization

  Familiarity information: SI used as a noun is uncommon.

 Dictionary entry details 

• SI (noun)

Sense 1

Meaning:

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

Classified under:

Nouns denoting substances

Synonyms:

atomic number 14; Si; silicon

Hypernyms ("Si" is a kind of...):

chemical element; element (any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter)

semiconducting material; semiconductor (a substance as germanium or silicon whose electrical conductivity is intermediate between that of a metal and an insulator; its conductivity increases with temperature and in the presence of impurities)

Holonyms ("Si" is a substance of...):

quartz (a hard glossy mineral consisting of silicon dioxide in crystal form; present in most rocks (especially sandstone and granite); yellow sand is quartz with iron oxide impurities)

clay (a very fine-grained soil that is plastic when moist but hard when fired)

feldspar; felspar (any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium)

granite (plutonic igneous rock having visibly crystalline texture; generally composed of feldspar and mica and quartz)

sand (a loose material consisting of grains of rock or coral)

silicone; silicone polymer (any of a large class of siloxanes that are unusually stable over a wide range of temperatures; used in lubricants and adhesives and coatings and synthetic rubber and electrical insulation)

Sense 2

Meaning:

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)

Classified under:

Nouns denoting quantities and units of measure

Synonyms:

International System; International System of Units; SI; SI system; SI unit; Systeme International; Systeme International d'Unites

Context example:

Today the United States is the only country in the world not totally committed to the Systeme International d'Unites

Hypernyms ("SI" is a kind of...):

metric system (a decimal system of weights and measures based on the meter and the kilogram and the second)

Sense 3

Meaning:

The syllable naming the seventh (subtonic) note of any musical scale in solmization

Classified under:

Nouns denoting communicative processes and contents

Synonyms:

si; te; ti

Hypernyms ("si" is a kind of...):

solfa syllable (one of the names for notes of a musical scale in solmization)

 Context examples 

A non-SI unit of pressure equal to 133,332 Pa or 1.316E10-3 standard atmosphere.

(Millimeter of Mercury, NCI Thesaurus)

Non-SI unit of pressure equal to 101 325 Pa.

(Atmosphere, NCI Thesaurus)

A non-SI manometric unit of pressure defined by a column of water at 4 degrees Celsius with a height of one millimeter.

(Millimeter of Water Column, NCI Thesaurus)

A SI derived unit of force.

(Newton, NCI Thesaurus)

EXAMPLE(S): A performing lab may have completed the observation or lab test using conventional units, but the sponsor may wish to have the test reported in SI units.

(Performed Clinical Result As Collected Indicator, NCI Thesaurus/BRIDG)

Are is a non-SI unit accepted for use with SI.

(Are, NCI Thesaurus)

A non-SI unit of energy or heat variously defined based on different conditions under which it is measured and the context of its use.

(Calorie Unit, NCI Thesaurus)

A unit of diffusion coefficient in SI system.

(Meter Squared per Second, NCI Thesaurus)

Meter per second squared is a SI unit of acceleration.

(Meter per Second Squared, NCI Thesaurus)

The non-SI unit of mass equal to 20 grains or 1.295 978 2 grams.

(Apothecaries Scruple, NCI Thesaurus)