adj.1 of ice; icy.
2 Geol. characterized or produced by the presence or agency of ice.
3 Chem. forming icelike crystals upon freezing (glacial acetic acid).
Phrases and idioms:
glacial epoch (or period) a period when ice-sheets were exceptionally extensive.
Derivatives:
glacially adv.
Etymology: F glacial or L glacialis icy f. glacies ice