What does "ferromagnetism" mean?

The phenomenon whereby certain substances can become permanent magnets when subjected to a magnetic field.

How do you pronounce "ferromagnetism"?

Pronounced //ˌfɛɹoʊˈmæɡnɪtɪzm//.

Common synonyms include: electromagnetism, hysteresis, magnetic alignment, magnetic ordering, magnetic property, magnetism.

/ˌfɛɹoʊˈmæɡnɪtɪzm/ noun

noun ·Rare ·Advanced level

Noun

1
The phenomenon whereby certain substances can become permanent magnets when subjected to a magnetic field. countable, uncountable
2
phenomenon exhibited by materials like iron (nickel or cobalt) that become magnetized in a magnetic field and retain their magnetism when the field is removed wordnet

From ferro- + magnetism.