- the assemblage of rocks, rich in silica and alumina, that comprise the continental portions of the upper layer of the earth's crust.
Origin of sial
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for sial
During the Mutiny of 1857 the Sial leader again proved his loyalty by serving in person on the British side.
Sialogogue, sī-al′o-gog, n. a drug which increases the secretion of saliva—also Sial′agogue.
- the silicon-rich and aluminium-rich rocks of the earth's continental upper crust, the most abundant individual rock being granite
C20: si (licon) + al (uminium)