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  • sis
    sis
    noun
  • -sis
    -sis
    a suffix appearing in loanwords from Greek, where it was used to form from verbs abstract nouns of action, process, state, condition, etc..
  • SIS
    SIS
    abbreviation
    (in Britain) Secret Intelligence Service
Synonyms

sis

1 American  
[sis] / sɪs /

noun

Informal.
  1. sister.


-sis 2 American  
  1. a suffix appearing in loanwords from Greek, where it was used to form from verbs abstract nouns of action, process, state, condition, etc..

    thesis; aphesis.


SIS 1 British  

abbreviation

  1. Also called: MI6.  (in Britain) Secret Intelligence Service

  2. (in New Zealand) Security Intelligence Service

"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

sis 2 British  
/ sɪs /

noun

  1. informal short for sister

"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

sis 3 British  
/ siːs, sɪs /

interjection

  1. informal an exclamation of disgust

"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 sis1

1825–35, shortened form; compare Dutch zus for zuster sister

Origin of -sis2

From Greek

Vocabulary lists containing sis

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.

See Examples For:

"Hey Sis, call me back when you get this. I was just calling to see how your day went! I love you to the moon & back sis," it read.

From BBC Sep. 3, 2026

You’ve said your sis won’t stop harping on your solution, which suggests there’s a deeper issue here.

From Slate Mar. 20, 2024

“Hey sis, what’s up? It’s been hot as hell over here,” read one of their messages, shared with The New York Times.

From New York Times Jun. 29, 2023

The message reads, “Love you too 4L & After thank u sis appreciate it FR.”

From Los Angeles Times Nov. 14, 2022

Then Daddy says, “Your big sis came to surprise you, Rae!”

From "Odd One Out" by Nic Stone

Sallay was promoted to head the SIS, Sri Lanka’s main intelligence agency, following Rajapaksa's victory, but was dismissed after Anura Kumara Dissanayake won the presidency in 2024, promising prosecutions of those behind the attacks.

From Barron's Feb. 25, 2026

Slovakia's domestic intelligence service, the SIS, has confirmed the claims, but has given few details.

From BBC Jan. 24, 2025

Sandu said that between October and December, Moldovan police and its Intelligence and Security Service, or SIS, have intervened in “several cases of organized criminal elements and stopped attempts at violence.”

From Washington Times Feb. 13, 2023

“It was a huge wake-up call for a lot of theater companies, and a very necessary one,” said Kathy Hsieh, co-executive producer for Seattle’s SIS Productions.

From Seattle Times May 26, 2022

Helmick had identified William as the head of the SIS, and she had coyly suggested that the agency was breaking foreign codes.

From "The Woman All Spies Fear" by Amy Butler Greenfield

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