sima1

[sahy-muh] /ˈsaɪ mə/
noun, Geology
1.
an assemblage of rocks, rich in silica and magnesium, that constitutes the lower layer of the earth's crust and is found beneath the ocean floors and the sial of continents.
Origin
< German (1909), equivalent to Latin si(licium) silicium + ma(gnesium) magnesium
Related forms
simatic
[sahy-mat-ik] /saɪˈmæt ɪk/ (Show IPA), adjective

sima2

[sahy-muh] /ˈsaɪ mə/
noun, Architecture
1.
the uppermost member of a full classical order, usually a cyma recta, representing a roof gutter; cymatium.
Origin
variant of cyma
British Dictionary definitions for sima

sima

/ˈsaɪmə/
noun
1.
the silicon-rich and magnesium-rich rocks of the earth's oceanic crust, the most abundant individual rock being basalt
2.
the earth's continental lower crust, probably comprised of gabbro rather than basalt
Derived Forms
simatic (saɪˈmætɪk) adjective
Word Origin
C20: from si(lica) + ma(gnesia)