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

This 58-room resort overlooking the Adriatic is actually two distinct properties joined by a narrow isthmus. — Condé Nast, Condé Nast Traveler, 7 Aug. 2026

Commonly straits are formed by tectonic activity, such as a fracture in an isthmus. — Scott Spires, Encyclopedia Britannica, 23 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. — The Conversation, Fortune, 3 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

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