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Synonyms

SD

1 American  

abbreviation

  1. the intelligence and counterespionage service of the Nazi SS.

SD 2 American  

abbreviation

  1. sea-damaged.

  2. South Dakota (approved especially for use with zip code).

  3. Statistics. standard deviation.

sd. 3 American  

abbreviation

  1. sound.

S/D 4 American  

abbreviation

  1. school district.

  2. sight draft.

s.d. 5 American  

abbreviation

  1. sine die.

  2. Statistics. standard deviation.

S.D. 6 American  

abbreviation

  1. doctor of science.

S.D. 7 American  

abbreviation

  1. sea-damaged.

  2. senior deacon.

  3. South Dakota.

  4. special delivery.

  5. Statistics. standard deviation.

SD 1 British  

abbreviation

  1. South Dakota

  2. Also: sd.  statistics standard deviation

"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

abbreviation

  1. Swaziland (international car registration)

"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
sd 2 British  

abbreviation

  1. sine die

  2. sound

  3. philosophy sense datum

"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
sd 3 British  

abbreviation

  1. Sudan

"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

Etymology

Origin of SD1

From the German word Sicherheitsdienst

Origin of S.D.6

From Latin Scientiae Doctor

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

There’s a joke on TikTok that one person in every group is the “digital camera friend,” wrangling everyone for photos and handling SD cards and adapters.

From The Wall Street Journal • Oct. 6, 2025

Edward Snowden removed information using a SD memory card he hid on some occasions in a Rubik’s cube.

From Salon • Jun. 30, 2025

It’s unclear if the device was able to transmit data over a Wi-Fi signal or if the camera had an SD card that would require the owner to retrieve the equipment to view the video.

From Los Angeles Times • Mar. 10, 2025

"We use these teeny recorders with an SD card that are specifically designed for recording wildlife acoustics," Ripa said.

From Science Daily • Apr. 20, 2024

The square which contains WA is in line S, column D. So I put down SD.

From The Treasure-Train by Reeve, Arthur B. (Arthur Benjamin)

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.