a large body of basalt, unusual in displaying perfect columnar jointing, exposed on a promontory on the northern coast of Northern Ireland.
Origin of Giant's Causeway
First recorded in 1770–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
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
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012