View source for Deci-

{{Short description|Metric system prefix meaning one tenth}}
{{Wiktionary|deci-}}
[[File:France, decim 1798-1799, the First Republic.jpg|thumb|250px|French 1 [[decime]] coin, equal to {{sfrac|1|10}} of a [[French franc|franc]]. [[French First Republic|First Republic]].]]
'''''Deci''''' (symbol '''d''') is a [[decimal prefix|decimal]] [[metric prefix|unit prefix]] in the [[metric system]] denoting a factor of one tenth. Proposed in 1793,<ref name="CTPM_1793">{{cite book|title=Instruction abrégée sur les mesures déduites de la grandeur de la Terre; uniformes pour toute la Rêpublique, et sur les Calculs relatifs à leur division décimale
|author=Commission temporaire de Poids & Mesures rêpublicaines, En exécution des Décrets de la Convention Nationale
|publisher=De l´imprimerie nationale exécutive du Louvre
|edition=Edition originale
|location=Paris, France
|language=fr
|date=1793
|url=https://archive.org/details/instructionabreg00hauy
|access-date=2015-10-09}}</ref> and adopted in 1795, the prefix comes from the Latin {{lang|la|decimus}}, meaning "tenth". Since 1960, the prefix is part of the [[International System of Units]] (SI).<ref>{{cite book
| title=The International System of Units (Si): The Metric System
| page=30
| publisher=DIANE Publishing
| year=1992
| url=https://books.google.com/books?id=y2-BDaoBVnwC&dq=si+derived+units+1960&pg=PA30
| isbn=9780941375740}}</ref><ref>{{cite web
| url=https://www.bipm.org/en/CGPM/db/11/12/
| title=Resolution 12 of the 11th CGPM
| date=1960
| publisher=[[BIPM]]
| access-date=2020-05-14
| archive-date=2020-04-08
| archive-url=https://web.archive.org/web/20200408155740/https://www.bipm.org/en/CGPM/db/11/12/
| url-status=dead
}}</ref>

A frequent use of the prefix is in the unit deciliter (dl), common in food recipes; many European homes have a deciliter measure for flour, water, etc. A common measure in engineering is the unit [[decibel]] for measuring ratios of [[Power, root-power, and field quantities|power and root-power]] quantities, such as sound level and electrical amplification.

Example
*The diameter of a [[compact disc]] is about 12 centimetres or 1.2 decimetres.<ref>{{cite web
| title=Universcale: From the nanoworld to the universe — The worlds we measure using our infinite yardstick.
| publisher=[[Nikon]]
| date=2013
| url=https://www.nikon.com/about/sp/universcale/
| url-status=live
| archive-url=https://web.archive.org/web/20170208212202/http://www.nikon.com/about/sp/universcale/index.htm
| archive-date=2017-02-08
| access-date=2017-02-08}}</ref>

==References==
{{Reflist}}

{{SI prefixes (infobox)}}

[[Category:SI prefixes]]