Giant's Causeway

American  

noun

1. a large body of basalt, unusual in displaying perfect columnar jointing, exposed on a promontory on the northern coast of Northern Ireland.

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Giant's Causeway British  

noun

1. a promontory of columnar basalt on the N coast of Northern Ireland, in Antrim: consists of several thousand pillars, mostly hexagonal, that were formed by the rapid cooling of lava and the inward contraction of the lava flow

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Etymology

Origin of Giant's Causeway

First recorded in 1770–80