Ruinous/ˈruːɪnəs/ Definition 1 of 3Pro Tip 1/3Consequence of Neglect Used when something is damaged due to lack of care or maintenance over time. His garden became ruinous after months of neglect. Pro Tip 2/3Beyond Repair Implies a state of damage so bad that it cannot be repaired or is not worth repairing. The old mill is in a ruinous condition and must be torn down. Pro Tip 3/3Outcome of Disaster Refers to the aftermath of a disastrous event like a storm, war, or financial crisis. A ruinous path was left in the tornado's wake.