\ 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

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 Kim Kardashian has taken a page from little sis Kylie Jenner's cosmetics empire and started her own IRL pop-up store in Los Angeles. Leah Prinzivalli, Allure, "Kim Kardashian Teases Inside of KKW Beauty L.A. Pop-Up Shop," 19 June 2018 Her little sis Kendall Jenner posted an undeniable thirst trap on Instagram, showing off her bootay while laying in a field of flowers, cloaked in a leopard print thong. Kelsey Stiegman, Seventeen, "Kendall Jenner Pulls a Kim Kardashian, Shows Full-Butt in a Leopard Print Thong," 25 Apr. 2018 But recently, the sportswear maker has become a hit with it girls Kim Kardashian West and younger sis Kylie Jenner. Charisse Jones, USA TODAY, "Call it a comeback but hot brands Fila, Dr. Martens, Polaroid have been here for years," 9 Mar. 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

18 Sep 2018

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Time Traveler for sis

The first known use of sis was in 1656

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Comments on sis

What made you want to look up sis? Please tell us where you read or heard it (including the quote, if possible).


alleviating pain or harshness

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