The Collaborative International Dictionary
Glacial \Gla"cial\, a. [L. glacialis, from glacies ice: cf. F. glacial.]
Pertaining to ice or to its action; consisting of ice; frozen; icy; esp., pertaining to glaciers; as, glacial phenomena.
--Lyell.-
(Chem.) Resembling ice; having the appearance and consistency of ice; -- said of certain solid compounds; as, glacial phosphoric or acetic acids.
Glacial acid (Chem.), an acid of such strength or purity as to crystallize at an ordinary temperature, in an icelike form; as acetic or carbolic acid.
Glacial drift (Geol.), earth and rocks which have been transported by moving ice, land ice, or icebergs; bowlder drift.
Glacial epoch or Glacial period (Geol.), a period during which the climate of the modern temperate regions was polar, and ice covered large portions of the northern hemisphere to the mountain tops.
Glacial theory or Glacial hypothesis. (Geol.) See Glacier theory, under Glacier.
WordNet
n. any period of time during which glaciers covered a large part of the earth's surface; "the most recent ice age was during the Pleistocene" [syn: ice age, glacial period]
from two million to 11 thousand years ago; extensive glaciation of the northern hemisphere; the time of human evolution [syn: Pleistocene, Pleistocene epoch]
Usage examples of "glacial epoch".
In his reading, he had come across a geologist's speculation that during a glacial epoch the Tarnack River had been blocked by a moraine-a gigantic mass of sand, rock and other debris deposited by the glacier that once had covered that entire region.
It was thickly wooded in spots, and in the centre, near the big dam, which held back the waters of an immense artificial lake, was a great hill, evidently a relic of some glacial epoch.