D defs.my
Entry 2 senses Webster, 1913

Glacial

/glāsh'-əl/ · Gla·cial · IPA /ˈɡleɪ.sɪəl/
01 a. Pertaining to ice or to its action; consisting of ice; frozen; icy; esp., pertaining to glaciers; as, glacial phenomena.
  1. 1.
    Pertaining to ice or to its action; consisting of ice; frozen; icy; esp., pertaining to glaciers; as, glacial phenomena.
  2. 2.
    Resembling ice; having the appearance and consistency of ice; -- said of certain solid compounds; as, glacial phosphoric or acetic acids.(Chem.)
Phrases & compounds
Glacial acid — 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 — earth and rocks which have been transported by moving ice, land ice, or icebergs; bowlder drift.
Glacial epoch — 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 — See Glacier theory, under Glacier.