Final answer:
The term 'mafic' is derived from 'magnesium' and 'ferric', referring to the iron and magnesium-rich content in these dark-colored igneous rocks.
Step-by-step explanation:
The term mafic indeed comes from the words magnesium and ferric, which refer to the high magnesium and iron content in these types of igneous rocks. Mafic rocks, being rich in magnesium and iron, typically have a darker color. The term is applied to an igneous rock that has a significant presence of dark-colored, ferromagnesian minerals such as pyroxene, olivine, and amphibole.
This distinguishes mafic rocks from felsic rocks - which are lighter in color due to the higher silica content - and from ultramafic rocks, which have an even greater content of magnesium and iron.