To mark a bill or a debt record as "paid".
To put an end to.
To terminate; to cancel (plans or expectations); to stop something once and for all.
The rain put paid to our plans for a picnic.
To demonstrate as completely false.
The young man standing outside the door, shaking like a leaf, looking like he was about to pee himself, put paid to his claim in a quavering voice, "I am not afraid!"