ETYM Old Eng. ruine, French ruine, from Latin ruina, from ruere, rutum, to fall with violence, to rush or tumble down.
1. A ruined building.
2. An event that results in destruction; SYN. ruination.

ETYM Late Lat. ruinatio.
The act of ruining, or the state of being ruined.

An act that makes a previous act of no effect (as if not done).