a. Of, relating to, or produced by a glacier.
b. Extremely slow, like the movement of a glacier: Work proceeded at a glacial pace.
a. often Glacial Characterized or dominated by the existence of glaciers. Used of a geologic epoch.
b. Pleistocene. See Table at geologic time.
3. Extremely cold; icy: a glacial rain. See Synonyms at cold.
4. Having the appearance of ice.
a. Lacking warmth and friendliness: a glacial stare.
b. Coldly detached: a glacial composure.
[French, from Old French, icy, from Latin glaciālis, from glaciēs, ice; see gel- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.