What does 'defeat' mean on card 125, and what does 'undiscover' do?

Question

Accepted Answer

'Defeat' works differently for each enemy: some are turned, some destroyed, some undiscovered. Undiscovering returns the card to its place in the box by serial number, so it can be discovered again later.

Kingdom Legacy: Feudal Kingdom

What does 'defeat' mean on card 125, and what does 'undiscover' do?