\ˈsis \

Definition of sis 

(Entry 1 of 3)

: sister usually used in direct address

Definition of SIS (Entry 2 of 3)

Secret Intelligence Service

Note: The Secret Intelligence Service is a British government agency that is responsible for the collection and analysis of information about foreign countries or groups.

plural -ses

Definition of -sis (Entry 3 of 3)

: process : action peristalsis

Examples of sis in a Sentence

Recent Examples on the Web: Noun

Today, however, Princess Beatrice traded in extravagance for something slightly more demure, so the attention would be all on her lil sis. Marina Liao, Marie Claire, "Princess Beatrice Wore a Ralph & Russo Dress to Princess Eugenie's Wedding," 12 Oct. 2018 Omg kim you’re beautiful sis but did the same guy who did Selena’s makeup for the MET gala do your makeup? Zoë Weiner, Teen Vogue, "Kim Kardashian's Spray Tan Gets Compared to Selena Gomez at the 2018 Met Gala," 10 July 2018 Witty big sis Khloe Kardashian couldn't resist the opportunity to compliment her sister with a joke. Isabel Greenberg, Harper's BAZAAR, "Khloe Kardashian Trolled Kendall Jenner's Bikini Instagram In the Best Way," 25 June 2018 Considering the support for the conservative legislation, perhaps GOP leaders placed the em-PHA-sis on the wrong syl-LA-ble. Chad Pergram, Fox News, "Proposed DACA pathway complicates border wall funding," 25 June 2018 Rolling up in a carriage, Eugenie, 28, and her older sis Princess Beatrice looked stunning on Thursday. Kayla Keegan, Good Housekeeping, "Princess Eugenie’s Royal Ascot Outfit Had a Deep Connection to Queen Elizabeth," 22 June 2018 But now, big sis Kim is ready to strike out on her own. Leah Prinzivalli, Allure, "Kim Kardashian Is Launching a KKW Beauty Nude Lipstick and Lip Liner Collection," 29 May 2018 But with her first baby in the picture, Kylie's softened to her big sis. Erica Gonzales, Harper's BAZAAR, "Kendall Jenner Reveals How She First Reacted to Kylie Jenner's Pregnancy," 10 May 2018 Just like her 4-year-old older sis, Mia Grace, Lena (Lay-na) Elizabeth is certainly a beautiful name. Kayla Keegan, Good Housekeeping, "How to Pronounce Zara and Mike Tindall's New Baby's Name," 27 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of sis


1656, in the meaning defined above

History and Etymology for sis

Noun suffix

Latin, from Greek, feminine suffix of action

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Last Updated

13 Nov 2018

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The first known use of sis was in 1656

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