1. Pertaining to ice or to its action; consisting of ice; frozen; icy; especially, pertaining to glaciers; as, glacial phenomena.
2. (Science: chemistry) Resembling ice; having the appearance and consistency of ice; said of certain solid compounds; as, glacial phosphoric or acetic acids.
(Science: chemistry) glacial acid see glacier theory, under glacier.
Origin: L. Glacialis, from glacies ice: cf. F. Glacial.