'mutiny' originates from Old French, specifically the word 'mutin' / 'mutiner', where the root is ultimately linked to Latin 'mutare' meaning 'to change'.

'mutiny' changed from Old French 'mutin' / 'mutiner' into Middle English forms (e.g. 'mutine') and eventually became the modern English word 'mutiny'.

Initially, it referred to disorder or rebellion (especially among troops or sailors); this core meaning has largely remained, though modern use can be broader (any organized refusal to obey authority).