[ sahy-al ]
/ ˈsaɪ æl /

noun Geology.

the assemblage of rocks, rich in silica and alumina, that comprise the continental portions of the upper layer of the earth's crust.
Compare sima1.

Origin of sial

1920–25; < German, equivalent to Si(licium) silicium + Al(uminium) aluminum

Related forms

si·al·ic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for sialic


/ (ˈsaɪəl) /


the silicon-rich and aluminium-rich rocks of the earth's continental upper crust, the most abundant individual rock being granite

Derived Forms

sialic (saɪˈælɪk), adjective

Word Origin for sial

C20: si (licon) + al (uminium)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for sialic


[ sī-ălĭk ]


Having or having the characteristics of saliva.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.