'nonreversible' is formed in modern English by adding the prefix 'non-' to 'reversible'. 'reversible' ultimately comes from Latin 'reversibilis', where 're-' meant 'back' and 'vertere' meant 'to turn'.

'reversible' came into English via Latin 'reversibilis' (through Old French/medieval borrowings) and Middle English forms; 'non-' is a native English/Latin-derived negative prefix added to create 'nonreversible' in modern usage.

Originally 'reversible' meant 'capable of being turned back' in a literal sense; over time it broadened to mean 'capable of being restored to a previous state.' 'nonreversible' therefore developed to mean 'not capable of being returned to a previous state.'