'unreducible' originates from Latin, specifically the word 'reducere,' where 're-' meant 'back' and 'ducere' meant 'to lead.' The prefix 'un-' negates the ability to lead back or reduce.

'reducere' transformed into the Old French word 'reducir,' and eventually became the modern English word 'reduce.' The prefix 'un-' was added to form 'unreducible.'

Initially, 'reducere' meant 'to lead back,' but over time, 'reduce' evolved to mean 'to make smaller or simpler.' 'Unreducible' negates this ability.