IPA: /ˈruːɪnəsnəs/
KK: /ˈruːɪnəsnəs/
The quality or state of causing destruction or damage; the condition of being harmful or disastrous.
The ruinousness of the storm left many homes destroyed.
Ruinousness → It is formed from "ruin" (from Latin *ruina*, meaning a fall or collapse) and the suffix "-ous" (meaning full of) combined with "-ness" (meaning the state of being). The word "ruinousness" refers to the state of being full of ruin or destruction.
Think of 'ruin' as a fall or collapse, and remember that 'ruinousness' means the state of being full of ruin.