sial

American

[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.

sial British

/ ˈsaɪəl, saɪˈælɪk /

noun

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

"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

Other Word Forms

sialic

adjective

Etymology

Origin of sial

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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023