isth·​mus | \ˈi-sməs \

Definition of isthmus 

1 : a narrow strip of land connecting two larger land areas

2 : a narrow anatomical part or passage connecting two larger structures or cavities

Examples of isthmus in a Sentence

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By blocking the Kokaral isthmus to save the North Aral, Kazakhstan has essentially given up on the southern part of the lake, and the Uzbeks down south aren't happy about it. Ken Jennings, Condé Nast Traveler, "The Aral Sea Is Refilling for the First Time in Decades," 25 June 2018 Kokaral had become a peninsula and then an isthmus as the water level dropped. Ken Jennings, Condé Nast Traveler, "The Aral Sea Is Refilling for the First Time in Decades," 25 June 2018 The 11768 Northport ZIP code extends to a potpourri of beachfront houses along the isthmus of Asharoken village, separating Northport Bay from Long Island Sound, and Eatons Neck, a hamlet of sprawling lawns and large homes. Marcelle Sussman Fischler, New York Times, "Northport, N.Y.: Old-Time Charm in a Waterfront Village," 2 May 2018 My uncles hopped off, driving stakes into the bank with large mallets and tying lines to keep the stern from drifting onto the low-lying isthmus. Sunset, "The Ultimate Venue for Your Next Family Vacay? A Houseboat," 22 Jan. 2018 The 1713 Treaty of Utrecht permanently ceded Gibraltar’s town, castle and port to Great Britain, but recovering the Rock—which is separated from Spanish territory by a narrow, sandy isthmus—has remained to this day an enduring objective for Spain. Stephen Brumwell, WSJ, "‘Gibraltar’ Review: When the Rock Was a Hard Place," 3 Apr. 2018 The state of Chiapas, located along the narrow isthmus in North America’s topographic waistline, acts like a funnel through which nearly all migrants must pass. Lauren Markham, The New Republic, "How efforts to block refugees and asylum-seekers from Europe have only made the global migration crisis more complex and harrowing," 26 Feb. 2018 Today, while there is evidence of some animals still slowly advancing South for the first time, the isthmus is a singular location to see and study annual migrations of millions of birds, mammals and reptiles. Roger Catlin, Smithsonian, "New Documentary Delights With Spectacular Visuals of the Panama Isthmus, A Migratory Superhighway," 12 Dec. 2017 Before the opening of the locks, the isthmus handled a weekly average volume of 53,000 containers, according to marine data provider PR News Service, which is closely followed by the industry. Costas Paris, WSJ, "The Panama Canal’s Big Bet Is Paying Off," 8 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'isthmus.' 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 isthmus

1555, in the meaning defined at sense 1

History and Etymology for isthmus

Latin, from Greek isthmos

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Statistics for isthmus

Last Updated

10 Oct 2018

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Time Traveler for isthmus

The first known use of isthmus was in 1555

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English Language Learners Definition of isthmus

: a narrow area of land that connects two larger land areas


isth·​mus | \ˈi-sməs \

Kids Definition of isthmus

: a narrow strip of land separating two bodies of water and connecting two larger areas of land


isth·​mus | \ˈis-məs \

Medical Definition of isthmus 

: a contracted anatomical part or passage connecting two larger structures or cavities: as

a : an embryonic constriction separating the midbrain from the hindbrain

b : the lower portion of the uterine corpus

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