si

1 of 3

noun

ˈsē How to pronounce si (audio)
: ti entry 1

Si

2 of 3

symbol

silicon

SI

3 of 3

abbreviation

International System of Units

Word History

Etymology

Noun

Italian

Abbreviation

French Système International d'Unités

First Known Use

Noun

1728, in the meaning defined above

Time Traveler
The first known use of si was in 1728

Phrases Containing si

Dictionary Entries Near si

SI

si

Sia

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Cite this Entry

“Si.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/si. Accessed 22 Dec. 2024.

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Kids Definition

si

noun
ˈsē How to pronounce si (audio)
: the seventh note of a scale : ti

Medical Definition

Si

1 of 2 symbol
silicon

SI

2 of 2 abbreviation
International System of Units
Etymology

Abbreviation

French Système International d'Unités

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