noun

1. one of the forms of pure metallic iron, having high magnetic permeability and occurring as a constituent of ordinary iron and steel
2. any of various ceramic, magnetic materials with poor electrical conductivity, containing ferric oxide and another metallic oxide: used in recording tape and computer memories
3. Geol. a grain, scale, or bit of red, brown, or yellow iron oxide in a rock

Etymology: < L ferrum, iron + -ite