si

[ see ]
/ si /

noun Music.

the syllable used for the seventh tone of a scale and sometimes for the tone B.

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Origin of si

First recorded in 1720–30; see origin at gamut

Definition for si (2 of 4)

Si

Symbol, Chemistry.

Definition for si (3 of 4)

Definition for si (4 of 4)

S.I.

Sandwich Islands.
Staten Island.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for si

British Dictionary definitions for si (1 of 5)

si1
/ (siː) /

noun

music a variant of te

British Dictionary definitions for si (2 of 5)

si2

the internet domain name for

Slovenia

British Dictionary definitions for si (3 of 5)

Si1

Si Kiang

/ (ʃiː) /

noun

a variant transliteration of the Chinese name for the Xi

British Dictionary definitions for si (4 of 5)

Si2

the chemical symbol for

silicon

British Dictionary definitions for si (5 of 5)

SI

symbol for

Système International (d'Unités)See SI unit

abbreviation for

NZ South Island
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for si (1 of 2)

Si

The symbol for the elementsilicon

Medical definitions for si (2 of 2)

SI

abbr.

Système International (d'Unités) (International System of Units)
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for si (1 of 2)

Si

The symbol for silicon.

Scientific definitions for si (2 of 2)

silicon
[ sĭlĭ-kŏn′ ]

Si

A metalloid element that occurs in both gray crystalline and brown noncrystalline forms. It is the second most abundant element in the Earth's crust and can be found only in silica and silicates. Silicon is used in glass, semiconductors, concrete, and ceramics. Atomic number 14; atomic weight 28.086; melting point 1,410°C; boiling point 2,355°C; specific gravity 2.33; valence 4. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.