reinforce

English built 'reinforce' by adding the prefix 're-' to an existing word 'inforce.' The 're-' itself traces back through Old French and Latin to Proto-Italic *wre-.

The word came together in English simply by stacking 're-' onto 'inforce,' rather than arriving whole from another language.

It shares its 're-' prefix with countless other English words built the same way, though the facts here don't name a specific cognate to point to.