'Magnetite' definitions:

Definition of 'magnetite'

(from WordNet)
noun
An oxide of iron that is strongly attracted by magnets [syn: magnetite, magnetic iron-ore]

Definition of 'Magnetite'

From: GCIDE
  • Magnetite \Mag"net*ite\, n. (Min.) An oxide of iron (Fe3O4) occurring in isometric crystals, also massive, of a black color and metallic luster. It is readily attracted by a magnet and sometimes possesses polarity, being then called loadstone. It is an important iron ore. Called also magnetic iron. [1913 Webster]