isthmus

noun

isth·​mus ˈi-sməs 

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

Recent Examples on the Web

Despite the geopolitical and financial constraints, the sea-level canal studies employed hundreds of researchers who increased knowledge of the isthmus and its human and nonhuman inhabitants. —The Conversation, Fortune, 3 Apr. 2026

Despite the geopolitical and financial constraints, the sea-level canal studies employed hundreds of researchers who increased knowledge of the isthmus and its human and nonhuman inhabitants. —Christine Keiner, The Conversation, 2 Apr. 2026

But this Central American country – a narrow isthmus stretching for 500 miles between Costa Rica (to the west) and Colombia (to the east) – offers far more to interest the curious traveller, said David Amsden in Condé Nast Traveller. —The Week Uk, TheWeek, 29 Mar. 2026

The city was built on an isthmus — a thin strip of land between two bodies of water. —Berly McCoy, NPR, 27 Feb. 2026

Word History

Etymology

Latin, from Greek isthmos

First Known Use

1555, in the meaning defined at sense 1

Kids Definition

isthmus

noun

isth·​mus ˈis-məs 

: a narrow strip of land connecting two larger land areas

Medical Definition

isthmus

noun

isth·​mus ˈis-məs 

: 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