'magnetisation' originates from Modern English, ultimately from Medieval Latin and French elements: 'magnet' (from Latin 'magnes' meaning 'lodestone') combined with the suffix '-isation' (from French '-isation', from Latin '-izare') to form the noun meaning 'the act or process of making magnetic'.

'magnet' came into English from Latin 'magnes' via Old English and Middle English forms; the verb-forming suffix from Greek/Latin gave rise to 'magnetise/magnetize' in Early Modern English, and the noun 'magnetisation' developed later to denote the process or resulting state.

Initially the root referred specifically to the lodestone or the property of attracting iron ('magnet'), but over time compounds and derivatives came to denote the action ('to make magnetic') and the quantitative property ('magnetisation') used in modern physics.