1 [usuallybeforenoun] (geology) connected with the Ice Age:
the glacial period (= the time when much of the northern half of the world was covered by ice)
2 (technical) caused or made by glaciers; connected with glaciers:
a glacial landscape * glacial deposits / erosion * glacial processes
3 (written) very cold; like ice:
glacial winds / temperatures * the glacial waters of the Arctic * The dining room was glacial.
4 (written) (used about people) cold and unfriendly; not showing feelings:
Her expression was glacial. * Relations between the two countries had always been glacial.
