'ex-fiancé' originates from French, specifically the word 'fiancé,' where 'fiancer' meant 'to betroth.' The prefix 'ex-' is used to denote 'former.'

'fiancé' changed from the French word 'fiancé' and eventually became the modern English word 'fiancé.' The prefix 'ex-' was added to indicate a past relationship.

Initially, it meant 'a person engaged to be married,' but with the prefix 'ex-,' it evolved to mean 'a former fiancé.'