Dictionary.com
Thesaurus.com
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

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.

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

But your sis and brother-in-law didn’t “hurt” him in the sense of showing malice or intending harm.

From Washington Post • Feb. 28, 2023

Reactivate your account and come get ya flowers sis!!

From Los Angeles Times • Feb. 21, 2023

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

From "Odd One Out" by Nic Stone

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.