simacommon nounEtymologyexpandfrom the first two letters of the names of the two chemical elements silicon and magnesium.Definition1. The lower part of the Earth's crust, rich in rocks containing magnesium silicates.flags.vieilligéologieexpandSynonymsmanteaucroûte océaniquePluralsimasTranslationsenglish:sima
english:simaenglish:sima