Glā'cial, a.
(-shal) (Synop., §130), a. [Lat. glacialis; glacies, ice; Fr. & Sp. glacial, It. glaciale.]
- Pertaining to ice or its action; icy; especially, pertaining to glaciers; as, glacial phenomena. Lyell.
- (Chem.) Having a glassy appearance, as crystals; as, water acidulated by twenty drops of glacial acetic acid. Eng. Cyc.
Glacial period (Geol.), a period of geologic time in which, as is supposed by some geologists, large portions of the northern hemisphere were covered with ice nearly to the summits of the highest mountains.